diff --git a/CHANGES b/CHANGES
--- a/CHANGES
+++ b/CHANGES
@@ -98,3 +98,11 @@
 
 0.2.3.1:
 		added cross spectrum
+		added cum_sum
+
+0.2.3.2:
+		copied Config.hs from hmatrix
+
+0.2.3.3:
+		updated for ghc 7.2
+		
diff --git a/Config.hs b/Config.hs
new file mode 100644
--- /dev/null
+++ b/Config.hs
@@ -0,0 +1,141 @@
+{-
+    GSL and LAPACK may require auxiliary libraries which depend on OS,
+    distribution, and implementation. This script tries to to find out
+    the correct link command for your system.
+    Suggestions and contributions are welcome.
+
+    By default we try to link -lgsl -llapack. This works in ubuntu/debian,
+    both with and without ATLAS.
+    If this fails we try different sets of additional libraries which are
+    known to work in some systems.
+
+    The desired libraries can also be explicitly given by the user using cabal
+    flags (e.g., -fmkl, -faccelerate) or --configure-option=link:lib1,lib2,lib3,...
+
+-}
+
+module Config(config) where
+
+import System.Process
+import System.Exit
+import System.Environment
+import System.Directory(createDirectoryIfMissing)
+import Data.List(isPrefixOf, intercalate)
+import Distribution.Simple.LocalBuildInfo
+import Distribution.Simple.Configure
+import Distribution.PackageDescription
+
+-- possible additional dependencies for the desired libs (by default gsl lapack)
+
+opts = [ ""                              -- Ubuntu/Debian
+       , "blas"
+       , "blas cblas"
+       , "cblas"
+       , "gslcblas"
+       , "blas gslcblas"
+       , "f77blas"
+       , "f77blas cblas atlas gcc_s"     -- Arch Linux (older version of atlas-lapack)
+       , "blas gslcblas gfortran"        -- Arch Linux with normal blas and lapack
+       ]
+
+-- compile a simple program with symbols from GSL and LAPACK with the given libs
+testprog bInfo buildInfo libs fmks =
+    "echo \"#include <gsl/gsl_sf_gamma.h>\nint main(){zgesvd_(); gsl_sf_gamma(5);}\""
+                     ++" > " ++ (buildDir bInfo) ++ "/dummy.c; gcc "
+                     ++ (join $ ccOptions buildInfo) ++ " "
+                     ++ (join $ cppOptions buildInfo) ++ " "
+                     ++ (join $ map ("-I"++) $ includeDirs buildInfo) ++ " " 
+                     ++ (buildDir bInfo) ++ "/dummy.c -o "
+                     ++ (buildDir bInfo) ++ "/dummy "
+                     ++ (join $ map ("-L"++) $ extraLibDirs buildInfo) ++ " "
+                     ++ (prepend "-l" $ libs) ++ " "
+                     ++ (prepend "-framework " fmks) ++ " > /dev/null 2> /dev/null"
+
+join = intercalate " "
+prepend x = unwords . map (x++) . words
+
+check bInfo buildInfo libs fmks = (ExitSuccess ==) `fmap` system (testprog bInfo buildInfo libs fmks)
+
+-- simple test for GSL
+gsl bInfo buildInfo = "echo \"#include <gsl/gsl_sf_gamma.h>\nint main(){gsl_sf_gamma(5);}\""
+           ++" > " ++ (buildDir bInfo) ++ "/dummy.c; gcc "
+           ++ (join $ ccOptions buildInfo) ++ " "
+           ++ (join $ cppOptions buildInfo) ++ " "
+           ++ (join $ map ("-I"++) $ includeDirs buildInfo) ++ " " 
+           ++ (buildDir bInfo) ++ "/dummy.c -o "
+           ++ (buildDir bInfo) ++ "/dummy "
+           ++ (join $ map ("-L"++) $ extraLibDirs buildInfo) ++ " -lgsl -lgslcblas"
+           ++ " > /dev/null 2> /dev/null"
+
+-- test for gsl >= 1.12
+gsl112 bInfo buildInfo =
+    "echo \"#include <gsl/gsl_sf_exp.h>\nint main(){gsl_sf_exprel_n_CF_e(1,1,0);}\""
+           ++" > " ++ (buildDir bInfo) ++ "/dummy.c; gcc " 
+           ++ (buildDir bInfo) ++ "/dummy.c "
+           ++ (join $ ccOptions buildInfo) ++ " "
+           ++ (join $ cppOptions buildInfo) ++ " "
+           ++ (join $ map ("-I"++) $ includeDirs buildInfo)
+           ++" -o " ++ (buildDir bInfo) ++ "/dummy "
+           ++ (join $ map ("-L"++) $ extraLibDirs buildInfo) ++ " -lgsl -lgslcblas"
+           ++ " > /dev/null 2> /dev/null"
+
+
+checkCommand c = (ExitSuccess ==) `fmap` system c
+
+-- test different configurations until the first one works
+try _ _ _ _ [] = return Nothing
+try l i b f (opt:rest) = do
+    ok <- check l i (b ++ " " ++ opt) f
+    if ok then return (Just opt)
+          else try l i b f rest
+
+-- read --configure-option=link:lib1,lib2,lib3,etc
+linkop = "link:"
+getUserLink = concatMap (g . drop (length linkop)) . filter (isPrefixOf linkop)
+    where g = map cs
+          cs ',' = ' '
+          cs x   = x
+
+config :: LocalBuildInfo -> IO HookedBuildInfo
+          
+config bInfo = do
+    putStr "Checking foreign libraries..."
+    args <- getArgs
+
+    let Just lib = library . localPkgDescr $ bInfo
+        buildInfo = libBuildInfo lib
+        base = unwords . extraLibs $ buildInfo
+        fwks = unwords . frameworks $ buildInfo
+        auxpref = getUserLink args
+
+    -- We extract the desired libs from hmatrix.cabal (using a cabal flags)
+    -- and from a posible --configure-option=link:lib1,lib2,lib3
+    -- by default the desired libs are gsl lapack.
+
+    let pref = if null (words (base ++ " " ++ auxpref)) then "gsl lapack" else auxpref
+        fullOpts = map ((pref++" ")++) opts
+
+    -- create the build directory (used for tmp files) if necessary
+    createDirectoryIfMissing True $ buildDir bInfo
+    
+    r <- try bInfo buildInfo base fwks fullOpts
+
+    case r of
+        Nothing -> do
+            putStrLn " FAIL"
+            g  <- checkCommand $ gsl bInfo buildInfo
+            if g
+                then putStrLn " *** Sorry, I can't link LAPACK."
+                else putStrLn " *** Sorry, I can't link GSL."
+            putStrLn " *** Please make sure that the appropriate -dev packages are installed."
+            putStrLn " *** You can also specify the required libraries using"
+            putStrLn " *** cabal install hmatrix --configure-option=link:lib1,lib2,lib3,etc."            
+            return (Just emptyBuildInfo { buildable = False }, [])
+        Just ops -> do
+            putStrLn $ " OK " ++ ops
+            g <- checkCommand $ gsl112 bInfo buildInfo
+            let hbi = if g
+                        then emptyBuildInfo { extraLibs = words ops}
+                        else emptyBuildInfo { extraLibs = words ops, ccOptions = ["-DGSL110"]}
+            return (Just hbi, [])
+
diff --git a/Setup.lhs b/Setup.lhs
--- a/Setup.lhs
+++ b/Setup.lhs
@@ -1,5 +1,18 @@
 #! /usr/bin/env runhaskell
 
 > import Distribution.Simple
+> import Distribution.Simple.Setup
+> import Distribution.PackageDescription
+> import Distribution.Simple.LocalBuildInfo
 
-> main = defaultMainWithHooks autoconfUserHooks
+> import System.Process(system)
+> import Config(config)
+
+> main = defaultMainWithHooks simpleUserHooks { confHook = c }
+
+> c x y = do
+>     binfo <- confHook simpleUserHooks x y
+>     pbi <- config binfo
+>     let pkg_descr = localPkgDescr binfo
+>     return $ binfo { localPkgDescr = updatePackageDescription pbi pkg_descr }
+
diff --git a/configure b/configure
deleted file mode 100644
--- a/configure
+++ /dev/null
@@ -1,3 +0,0 @@
-#! /bin/sh
-
-runhaskell configure.hs $*
diff --git a/configure.hs b/configure.hs
deleted file mode 100644
--- a/configure.hs
+++ /dev/null
@@ -1,142 +0,0 @@
-#! /usr/bin/env runhaskell
-{- configure.hs for hsignal, copied from hmatrix
-   ------------------------
-
-    GSL and LAPACK may require auxiliary libraries which depend on OS,
-    distribution, and implementation. This script tries to to find out
-    the correct link command for your system.
-    Suggestions and contributions are welcome.
-
-    By default we try to link -lgsl -llapack. This works in ubuntu/debian,
-    both with and without ATLAS.
-    If this fails we try different sets of additional libraries which are
-    known to work in some systems.
-
-    The desired libraries can also be explicitly given by the user using cabal
-    flags (e.g., -fmkl, -faccelerate) or --configure-option=link:lib1,lib2,lib3,...
-
--}
-
-import System
-import System.Directory(createDirectoryIfMissing,getCurrentDirectory)
-import Data.List(isPrefixOf, intercalate)
-import Distribution.Simple.LocalBuildInfo
-import Distribution.Simple.Configure
-import Distribution.PackageDescription
-
--- possible additional dependencies for the desired libs (by default gsl lapack)
-
-opts = [ ""                              -- Ubuntu/Debian
-       , "blas"
-       , "blas cblas"
-       , "cblas"
-       , "gslcblas"
-       , "blas gslcblas"
-       , "f77blas"
-       , "f77blas cblas atlas gcc_s"     -- Arch Linux (older version of atlas-lapack)
-       , "blas gslcblas gfortran"        -- Arch Linux with normal blas and lapack
-       ]
-
--- compile a simple program with symbols from GSL and LAPACK with the given libs
-testprog bInfo buildInfo libs fmks =
-    "echo \"#include <gsl/gsl_sf_gamma.h>\nint main(){zgesvd_(); gsl_sf_gamma(5);}\""
-                     ++" > " ++ (buildDir bInfo) ++ "/dummy.c; gcc "
-                     ++ (join $ ccOptions buildInfo) ++ " "
-                     ++ (join $ cppOptions buildInfo) ++ " "
-                     ++ (join $ map ("-I"++) $ includeDirs buildInfo) ++ " " 
-                     ++ (buildDir bInfo) ++ "/dummy.c -o "
-                     ++ (buildDir bInfo) ++ "/dummy "
-                     ++ (join $ map ("-L"++) $ extraLibDirs buildInfo) ++ " "
-                     ++ (prepend "-l" $ libs) ++ " "
-                     ++ (prepend "-framework " fmks) ++ " > /dev/null 2> /dev/null"
-
-join = intercalate " "
-prepend x = unwords . map (x++) . words
-
-check bInfo buildInfo libs fmks = (ExitSuccess ==) `fmap` system (testprog bInfo buildInfo libs fmks)
-
--- simple test for GSL
-gsl bInfo buildInfo = "echo \"#include <gsl/gsl_sf_gamma.h>\nint main(){gsl_sf_gamma(5);}\""
-           ++" > " ++ (buildDir bInfo) ++ "/dummy.c; gcc "
-           ++ (join $ ccOptions buildInfo) ++ " "
-           ++ (join $ cppOptions buildInfo) ++ " "
-           ++ (join $ map ("-I"++) $ includeDirs buildInfo) ++ " " 
-           ++ (buildDir bInfo) ++ "/dummy.c -o "
-           ++ (buildDir bInfo) ++ "/dummy "
-           ++ (join $ map ("-L"++) $ extraLibDirs buildInfo) ++ " -lgsl -lgslcblas"
-           ++ " > /dev/null 2> /dev/null"
-
--- test for gsl >= 1.12
-gsl112 bInfo buildInfo =
-    "echo \"#include <gsl/gsl_sf_exp.h>\nint main(){gsl_sf_exprel_n_CF_e(1,1,0);}\""
-           ++" > " ++ (buildDir bInfo) ++ "/dummy.c; gcc " 
-           ++ (buildDir bInfo) ++ "/dummy.c "
-           ++ (join $ ccOptions buildInfo) ++ " "
-           ++ (join $ cppOptions buildInfo) ++ " "
-           ++ (join $ map ("-I"++) $ includeDirs buildInfo)
-           ++" -o " ++ (buildDir bInfo) ++ "/dummy "
-           ++ (join $ map ("-L"++) $ extraLibDirs buildInfo) ++ " -lgsl -lgslcblas"
-           ++ " > /dev/null 2> /dev/null"
-
-
-checkCommand c = (ExitSuccess ==) `fmap` system c
-
--- test different configurations until the first one works
-try _ _ _ _ [] = return Nothing
-try l i b f (opt:rest) = do
-    ok <- check l i (b ++ " " ++ opt) f
-    if ok then return (Just opt)
-          else try l i b f rest
-
--- read --configure-option=link:lib1,lib2,lib3,etc
-linkop = "link:"
-getUserLink = concatMap (g . drop (length linkop)) . filter (isPrefixOf linkop)
-    where g = map cs
-          cs ',' = ' '
-          cs x   = x
-
-main = do
-    dir <- getCurrentDirectory
-    putStrLn $ "Current directory: " ++ dir
-
-    putStr "Checking foreign libraries..."
-
-    args <- getArgs
-    Just bInfo <- maybeGetPersistBuildConfig "dist"
-
-    let Just lib = library . localPkgDescr $ bInfo
-        buildInfo = libBuildInfo lib
-        base = unwords . extraLibs $ buildInfo
-        fwks = unwords . frameworks $ buildInfo
-        auxpref = getUserLink args
-
-    -- We extract the desired libs from hsignal.cabal (using a cabal flags)
-    -- and from a posible --configure-option=link:lib1,lib2,lib3
-    -- by default the desired libs are gsl lapack.
-
-    let pref = if null (words (base ++ " " ++ auxpref)) then "gsl lapack" else auxpref
-        fullOpts = map ((pref++" ")++) opts
-
-    -- create the build directory (used for tmp files) if necessary
-    createDirectoryIfMissing True $ buildDir bInfo
-    
-    r <- try bInfo buildInfo base fwks fullOpts
-    case r of
-        Nothing -> do
-            putStrLn " FAIL"
-            g  <- checkCommand $ gsl bInfo buildInfo
-            if g
-                then putStrLn " *** Sorry, I can't link LAPACK."
-                else putStrLn " *** Sorry, I can't link GSL."
-            putStrLn " *** Please make sure that the appropriate -dev packages are installed."
-            putStrLn " *** You can also specify the required libraries using"
-            putStrLn " *** cabal install hsignal --configure-option=link:lib1,lib2,lib3,etc."
-            writeFile "hsignal.buildinfo" ("buildable: False\n")
-        Just ops -> do
-            putStrLn " OK"
-            g <- checkCommand $ gsl112 bInfo buildInfo
-            writeFile "hsignal.buildinfo" $ "extra-libraries: " ++
-                ops ++ "\n" ++
-                if g
-                    then ""
-                    else "cc-options: -DGSL110\n"
diff --git a/hsignal.cabal b/hsignal.cabal
--- a/hsignal.cabal
+++ b/hsignal.cabal
@@ -1,5 +1,5 @@
 Name:               hsignal
-Version:            0.2.3.1
+Version:            0.2.3.3
 License:            BSD3
 License-file:       LICENSE
 Copyright:          (c) A.V.H. McPhail 2010, 2011
@@ -18,13 +18,13 @@
      .
      Feature requests, suggestions, and bug fixes welcome.
 Category:           Math
-tested-with:        GHC ==7.0.1
+tested-with:        GHC ==7.0.3
 
 cabal-version:      >=1.8
 
 build-type:         Custom
 
-extra-source-files: configure configure.hs README INSTALL CHANGES
+extra-source-files: Config.hs README INSTALL CHANGES
 extra-tmp-files:    hsignal.buildinfo
 
 flag mkl
diff --git a/lib/Numeric/Signal.hs b/lib/Numeric/Signal.hs
--- a/lib/Numeric/Signal.hs
+++ b/lib/Numeric/Signal.hs
@@ -30,11 +30,11 @@
                        cross_covariance,cross_correlation,cross_spectrum,
                        auto_covariance,auto_correlation,
                        -- * Preprocessing
-                       cumulative_sum,
                        detrend,
                        resize,
                        downsample,
                        deriv,
+                       cumulative_sum
                 ) where
 
 -----------------------------------------------------------------------------
@@ -295,14 +295,6 @@
 
 -----------------------------------------------------------------------------
 
--- | cumulative sum of a series
-cumulative_sum :: S.Filterable a =>
-                 Vector a 
-               -> Vector a
-cumulative_sum = S.cumulative_sum_
-
------------------------------------------------------------------------------
-
 -- | coefficients of a Hamming window
 hamming :: S.Filterable a =>
           Int           -- ^ length
@@ -317,7 +309,13 @@
 deriv :: S.Filterable a => Vector a -> Vector a
 deriv = S.deriv_
 
--- | unwrap the phase of signal (input expected to be within (-pi,pi)
+-- | cumulative sum of a series
+cumulative_sum :: S.Filterable a =>
+                 Vector a 
+               -> Vector a
+cumulative_sum = S.cumulative_sum_
+
+-- | unwrap the phase of signal (input expected to be within (-pi,pi))
 unwrap :: S.Filterable a => Vector a -> Vector a
 unwrap = S.unwrap_
 
diff --git a/lib/Numeric/Signal/Multichannel.hs b/lib/Numeric/Signal/Multichannel.hs
--- a/lib/Numeric/Signal/Multichannel.hs
+++ b/lib/Numeric/Signal/Multichannel.hs
@@ -124,7 +124,7 @@
           l <- get
           de <- get
           f <- get
-          (d :: I.Array Int (a,a,Vector Word64)) <- get
+          (d :: I.Array Int (Double,Double,Vector Word64)) <- get
           return $! (MC s p c l de f (seq d (fmap convert) d))
               where convert (mi,ma,v) = mapVector (\x -> ((fromIntegral x)) / (fromIntegral (maxBound :: Word64)) * (ma - mi) + mi) v
 
@@ -148,7 +148,7 @@
           l <- get
           de <- get
           f <- get
-          (d :: I.Array Int (a,a,Vector Word32)) <- get
+          (d :: I.Array Int (Float,Float,Vector Word32)) <- get
           return $! (MC s p c l de f (seq d (fmap convert) d))
               where convert (mi,ma,v) = mapVector (\x -> ((fromIntegral x)) / (fromIntegral (maxBound :: Word32)) * (ma - mi) + mi) v
 
@@ -172,7 +172,7 @@
           l <- get
           de <- get
           f <- get
-          (d :: I.Array Int ((a,a,Vector Word64),(a,a,Vector Word64))) <- get
+          (d :: I.Array Int ((Double,Double,Vector Word64),(Double,Double,Vector Word64))) <- get
           return $! (MC s p c l de f (seq d (fmap (\(r,i) -> toComplex (convert r,convert i)) d)))
               where convert (mi,ma,v) = mapVector (\x -> ((fromIntegral x)) / (fromIntegral (maxBound :: Word64)) * (ma - mi) + mi) v
 
@@ -198,7 +198,7 @@
           l <- get
           de <- get
           f <- get
-          (d :: I.Array Int ((a,a,Vector Word32),(a,a,Vector Word32))) <- get
+          (d :: I.Array Int ((Float,Float,Vector Word32),(Float,Float,Vector Word32))) <- get
           return $! (MC s p c l de f (seq d (fmap (\(r,i) -> toComplex (convert r,convert i)) d)))
               where convert (mi,ma,v) = mapVector (\x -> ((fromIntegral x)) / (fromIntegral (maxBound :: Word32)) * (ma - mi) + mi) v