diff --git a/CHANGES b/CHANGES
--- a/CHANGES
+++ b/CHANGES
@@ -29,4 +29,7 @@
 		removed warning causes in Distribution.Discrete/Continuous
 		added fromVectors, modified fromMatrix in Histogram(2D)		
 		added countInstance, probability to Histogram(2D)
+		added probPair to Histogram2D
 
+0.1.2.3:
+		fixed imports to reflect changes in hmatrix
diff --git a/hmatrix-gsl-stats.cabal b/hmatrix-gsl-stats.cabal
--- a/hmatrix-gsl-stats.cabal
+++ b/hmatrix-gsl-stats.cabal
@@ -1,5 +1,5 @@
 Name:               hmatrix-gsl-stats
-Version:            0.1.2.2
+Version:            0.1.2.3
 License:            GPL
 License-file:       LICENSE
 Copyright:          (c) A.V.H. McPhail 2010
@@ -14,7 +14,9 @@
      Relieves the burden of alloc/free routines and is otherwise essentially 1:1
      .
      Documentation can be found at <http://www.gnu.org/software/gsl/manual/>
-
+     .
+     When hmatrix is installed with -fvector, the vector type is Data.Vector.Storable
+     from the vector package.
 Category:           Math, Statistics
 tested-with:        GHC ==6.12.1
 
diff --git a/lib/Numeric/GSL/Histogram.hs b/lib/Numeric/GSL/Histogram.hs
--- a/lib/Numeric/GSL/Histogram.hs
+++ b/lib/Numeric/GSL/Histogram.hs
@@ -50,8 +50,8 @@
 --import Data.Packed.Matrix hiding(toLists)
 import Data.Packed.Development
 
---import Numeric.LinearAlgebra.Linear
-import Numeric.LinearAlgebra.Algorithms hiding(add,multiply,divide,scale)
+import Numeric.LinearAlgebra.Algorithms hiding (multiply)
+import Numeric.LinearAlgebra.Linear hiding (add,divide,scale)
 import Numeric.LinearAlgebra.Interface()
 
 --import Control.Monad
diff --git a/lib/Numeric/GSL/Histogram2D.hs b/lib/Numeric/GSL/Histogram2D.hs
--- a/lib/Numeric/GSL/Histogram2D.hs
+++ b/lib/Numeric/GSL/Histogram2D.hs
@@ -51,7 +51,8 @@
 import Data.Packed.Matrix
 import Data.Packed.Development
 
-import Numeric.LinearAlgebra.Algorithms hiding(add,multiply,divide,scale)
+import Numeric.LinearAlgebra.Algorithms hiding (multiply)
+import Numeric.LinearAlgebra.Linear hiding (add,divide,scale)
 import Numeric.LinearAlgebra.Interface()
 
 --import Control.Monad
@@ -77,19 +78,16 @@
 
 -----------------------------------------------------------------------------
 
--- This Storable instance for Complex is binary compatible with C99, C++ and
--- Fortran complex data types.
 instance (Storable a) => Storable (a,a) where
     sizeOf z        = 2 * sizeOf (fst z)
     alignment z     = alignment (fst z)
     peek p          = do let q = castPtr p
-                         r <- peek q
-                         i <- peekElemOff q 1
-                         return (r,i)
-    poke p (r,i) = do let q = (castPtr p)
-                      poke q r
-                      pokeElemOff q 1 i
-
+                         a <- peek q
+                         b <- peekElemOff q 1
+                         return (a,b)
+    poke p (a,b) = do let q = (castPtr p)
+                      poke q a
+                      pokeElemOff q 1 b
 
 -----------------------------------------------------------------------------
 
@@ -433,9 +431,7 @@
 
 -- | find the joint probability of occuring for each element of the input vector pair
 probPaired :: Histogram2D -> (Vector (Double,Double)) -> Vector Double
-probPaired h z = let l = unzip $ toList z
-                     z' = (fromList $ fst l,fromList $ snd l)
-                 in prob h z'
+probPaired h z = (countPaired h z) / (scalar $ sum h)
 
 -----------------------------------------------------------------------------
 
@@ -650,7 +646,7 @@
 -----------------------------------------------------------------------------
 -----------------------------------------------------------------------------
 -----------------------------------------------------------------------------
-
+{-
 unzipPair :: Vector (Double,Double) -> (Vector Double,Vector Double)
 unzipPair v = unsafePerformIO $ do
               a <- createVector $ dim v
@@ -659,5 +655,5 @@
               return (a,b)
 
 foreign import ccall "histogram-aux.h unzip_double_pair" histogram2d_unzip_double_pair :: CInt -> Ptr (Double,Double) -> CInt -> Ptr Double -> CInt -> Ptr Double -> IO CInt
-
+-}
 -----------------------------------------------------------------------------