diff --git a/Network/XmlRpc/DTD_XMLRPC.hs b/Network/XmlRpc/DTD_XMLRPC.hs
--- a/Network/XmlRpc/DTD_XMLRPC.hs
+++ b/Network/XmlRpc/DTD_XMLRPC.hs
@@ -3,7 +3,7 @@
 import Text.XML.HaXml.Xml2Haskell
 import Text.XML.HaXml.OneOfN
 import Data.Char (isSpace)
-import Prelude (all, concatMap, (++), maybe)
+import Prelude hiding (String, Int, Double)
 import qualified Prelude
 
 
diff --git a/Network/XmlRpc/Internals.hs b/Network/XmlRpc/Internals.hs
--- a/Network/XmlRpc/Internals.hs
+++ b/Network/XmlRpc/Internals.hs
@@ -210,17 +210,21 @@
     fromValue :: Monad m => Value -> Err m a
     getType :: a -> Type
 
-typeError :: Monad m => Type -> Value -> Err m a
-typeError t v = fail ("Wanted: "  
-		     -- ++ show (getType t)
-		      ++ "', got: '" 
-		      ++ showXml (toXRValue v) ++ "'")
+typeError :: (XmlRpcType a, Monad m) => Value -> Err m a
+typeError v = withType $ \t ->
+       fail ("Wanted: "  
+	     ++ show (getType t)
+	     ++ "', got: '" 
+	     ++ showXml (toXRValue v) ++ "'") `asTypeOf` return t
 
+-- a type hack for use in 'typeError'
+withType :: (a -> Err m a) -> Err m a
+withType f = f undefined
 
 simpleFromValue :: (Monad m, XmlRpcType a) => (Value -> Maybe a) 
 		-> Value -> Err m a
 simpleFromValue f v = 
-    maybe (typeError (getType (fromJust (f v))) v) return (f v)
+    maybe (typeError v) return (f v)
 
 
 -- | Exists to allow explicit type conversions.
@@ -272,14 +276,8 @@
 instance XmlRpcType a => XmlRpcType [a] where
     toValue = ValueArray . map toValue 
     fromValue v = case v of
-			 ValueArray _ -> r
-			 -- FIXME: I am using TArray here because for
-			 -- some reason Hugs Nov 2003 requires a XmlRpcRpc [a]
-			 -- constraint on fromValue (which is not 
-			 -- legal haskell) to do (getType t) here.
-			 _ -> r >>= \t -> typeError TArray v
-	where ValueArray xs = v
-	      r = mapM fromValue xs
+			 ValueArray xs -> mapM fromValue xs
+			 _ -> typeError v
     getType _ = TArray
 
 -- FIXME: struct elements may have different types
@@ -287,10 +285,8 @@
     toValue xs = ValueStruct [(n, toValue v) | (n,v) <- xs]
 
     fromValue v = case v of
-		  ValueStruct _ -> r
-		  _ -> r >>= \t -> typeError (getType t) v
-	where ValueStruct xs = v
-	      r = mapM (\ (n,v) -> liftM ((,) n) (fromValue v)) xs
+		  ValueStruct xs -> mapM (\ (n,v) -> liftM ((,) n) (fromValue v)) xs
+		  _ -> typeError v
     getType _ = TStruct
 
 -- | Get a field value from a (possibly heterogeneous) struct.
diff --git a/Network/XmlRpc/Server.hs b/Network/XmlRpc/Server.hs
--- a/Network/XmlRpc/Server.hs
+++ b/Network/XmlRpc/Server.hs
@@ -74,15 +74,22 @@
 			      v <- handleIO x
 			      return (Return (toValue v))
     toFun _ _ = fail "Too many arguments"
-    sig (_::IO a) = ([], getType (undefined::a))
+    sig x = ([], getType (mType x))
 
 instance (XmlRpcType a, XmlRpcFun b) => XmlRpcFun (a -> b) where
     toFun f (MethodCall n (x:xs)) = do
 				  v <- fromValue x
 				  toFun (f v) (MethodCall n xs)
     toFun _ _ = fail "Too few arguments"
-    sig (f::a->b) = let (as, r) = sig (undefined::b) 
-			in (getType (undefined::a) : as, r)
+    sig f = let (a,b) = funType f
+                (as, r) = sig b
+             in (getType a : as, r)
+
+mType :: m a -> a
+mType _ = undefined
+
+funType :: (a -> b) -> (a, b)
+funType _ = (undefined, undefined)
 
 -- FIXME: always returns error code 0
 errorToResponse :: ServerResult -> IO MethodResponse
diff --git a/haxr.cabal b/haxr.cabal
--- a/haxr.cabal
+++ b/haxr.cabal
@@ -1,7 +1,8 @@
 Name: haxr
-Version: 3000.0.0
+Version: 3000.0.1
+Cabal-version: >=1.2
+Build-type: Simple
 Copyright: Bjorn Bringert, 2003-2006
-Build-depends: base, mtl, network, HaXml >= 1.13 && < 1.14, HTTP >= 1.0
 License: BSD4
 License-file: LICENSE
 Author: Bjorn Bringert <bjorn@bringert.net>
@@ -11,13 +12,21 @@
 Description:
         HaXR is a library for writing XML-RPC 
         client and server applications in Haskell.
-Exposed-Modules:
+
+Flag split-base
+
+Library
+  Build-depends: mtl, network, HaXml >= 1.13 && < 1.14, HTTP >= 1.0
+  if flag(split-base)
+    Build-depends: base >= 3.0, array, old-time, old-locale
+  else
+    Build-depends: base < 3.0
+  Exposed-Modules:
         Network.XmlRpc.Client,
         Network.XmlRpc.Server,
         Network.XmlRpc.Internals,
         Network.XmlRpc.Introspect
-Other-Modules:
+  Other-Modules:
         Network.XmlRpc.Base64,
         Network.XmlRpc.DTD_XMLRPC
-Extensions: OverlappingInstances, TypeSynonymInstances
-GHC-options: -O2
+  Extensions: OverlappingInstances, TypeSynonymInstances, FlexibleInstances