diff --git a/TV.cabal b/TV.cabal
--- a/TV.cabal
+++ b/TV.cabal
@@ -1,5 +1,5 @@
 Name:                TV
-Version:             0.4
+Version:             0.4.2
 Synopsis:	     Tangible Values -- composable interfaces
 Category:            Interfaces
 Description:
@@ -21,11 +21,11 @@
 Maintainer:          conal@conal.net
 Homepage:            http://haskell.org/haskellwiki/TV
 Package-Url:	     http://darcs.haskell.org/packages/TV
-Copyright:           (c) 2006 by Conal Elliott
+Copyright:           (c) 2006,2009 by Conal Elliott
 License:             BSD3
 Stability:	     experimental
 Hs-Source-Dirs:      src
-Build-Depends:       base, DeepArrow, TypeCompose >= 0.2
+Build-Depends:       base<5, DeepArrow>=0.3.1, TypeCompose >= 0.2
 tested-with:	     GHC==6.6
 build-type:	     Simple
 Exposed-Modules:     
@@ -39,4 +39,4 @@
                      Interface.TV.Defaults
 Extra-Source-Files:  
                      Examples
-ghc-options:         -W
+ghc-options:         -Wall
diff --git a/src/Examples.hs b/src/Examples.hs
--- a/src/Examples.hs
+++ b/src/Examples.hs
@@ -1,8 +1,7 @@
 {-# LANGUAGE OverlappingInstances, UndecidableInstances
-           , IncoherentInstances, FlexibleContexts #-}
--- For ghc 6.6 compatibility
--- {-# OPTIONS -fglasgow-exts #-}
-
+           , IncoherentInstances, FlexibleContexts 
+           , FlexibleInstances
+           #-}
 ---- Some TV examples.  See also GuiTV.
 
 module Examples where
@@ -10,6 +9,7 @@
 import Data.List (sort)
 import Control.Compose (cofmap,OI)
 import Control.Arrow.DeepArrow ((->|))
+import Data.FunArr
 
 -- TypeCompose
 import Data.Title
@@ -33,14 +33,17 @@
 -- GHC wants to use the [a] rather than the String instances of DefaultIn
 -- and DefaultOut.  I thought the rule is most specific instance wins.
 
---  This one reverses twice
-revTwice :: CTV (String -> String)
-revTwice = reverseT ->| reverseT
+-- --  This one reverses twice
+-- revTwice :: CTV (String -> String)
+-- revTwice = reverseT ->| reverseT
 
 -- Same problem with more general type:
 --   revTwice :: (Read a, Show a, CommonIns src, CommonOuts snk) =>
 --               TV src snk ([a] -> [a])
 
+-- I'm getting a type error even with the more specifically-typed
+-- revTwice.  "Could not deduce (FunArr ...)".  Is it a bug in
+-- type-checking with mutual dependencies?   Investigate.
 
 
 ---- IO examples
diff --git a/src/Interface/TV/Common.hs b/src/Interface/TV/Common.hs
--- a/src/Interface/TV/Common.hs
+++ b/src/Interface/TV/Common.hs
@@ -1,7 +1,5 @@
 {-# LANGUAGE Rank2Types, TypeOperators, TypeSynonymInstances,
     PatternGuards, FlexibleInstances #-}
--- For ghc 6.6 compatibility
--- {-# OPTIONS -fglasgow-exts #-}
 
 ----------------------------------------------------------------------
 -- |
diff --git a/src/Interface/TV/Defaults.hs b/src/Interface/TV/Defaults.hs
--- a/src/Interface/TV/Defaults.hs
+++ b/src/Interface/TV/Defaults.hs
@@ -1,8 +1,6 @@
 {-# LANGUAGE MultiParamTypeClasses, OverlappingInstances
            , TypeSynonymInstances, FlexibleInstances, UndecidableInstances
            , IncoherentInstances #-}
--- For ghc 6.6 compatibility
--- {-# OPTIONS -fglasgow-exts -fallow-overlapping-instances -fallow-incoherent-instances #-}
 
 ----------------------------------------------------------------------
 -- |
diff --git a/src/Interface/TV/Input.hs b/src/Interface/TV/Input.hs
--- a/src/Interface/TV/Input.hs
+++ b/src/Interface/TV/Input.hs
@@ -1,8 +1,4 @@
 {-# LANGUAGE GADTs, KindSignatures #-}
--- For ghc 6.6 compatibility
--- {-# OPTIONS -fglasgow-exts #-}
-
-
 ----------------------------------------------------------------------
 -- |
 -- Module      :  Interface.TV.Input
diff --git a/src/Interface/TV/OFun.hs b/src/Interface/TV/OFun.hs
--- a/src/Interface/TV/OFun.hs
+++ b/src/Interface/TV/OFun.hs
@@ -1,7 +1,5 @@
-{-# LANGUAGE MultiParamTypeClasses #-}
--- For ghc 6.6 compatibility
--- {-# OPTIONS -fglasgow-exts #-}
-
+{-# LANGUAGE MultiParamTypeClasses, CPP #-}
+{-# OPTIONS -fno-warn-orphans #-}
 ----------------------------------------------------------------------
 -- |
 -- Module      :  Interface.TV.OFun
@@ -17,12 +15,25 @@
 
 module Interface.TV.OFun (OX,OFun, wrapO{-,wrapAO-}) where
 
+#if __GLASGOW_HASKELL__ >= 609
+import Control.Category
+import Prelude hiding ((.), id)
+#endif
+
 import Control.Arrow
+#if __GLASGOW_HASKELL__ < 610
+                      hiding (pure)
+#endif
 
+
 import Control.Compose (Cofunctor(..))
 
 import Data.FunArr
 import Control.Arrow.DeepArrow
+#if __GLASGOW_HASKELL__ >= 609
+import Control.Category
+import Prelude hiding ((.), id)
+#endif
 
 import Interface.TV.Output
 import Interface.TV.Input
@@ -36,14 +47,21 @@
 
 -- TODO: consider generalizing from "->" in IFun?
 
+#if __GLASGOW_HASKELL__ >= 609
+instance Category (OFun dom ran) where
+  id              = idA
+  OFun g . OFun f = OFun (g . f)
+#endif
+
 instance Arrow (OFun dom ran) where
   -- (a->b) -> OFun dom ran a b
   arr = error "Interface.TV.OFun: no 'arr' method"
         -- We could use the following definition instead.
         -- const $ OFun (const OEmpty)
-
+#if __GLASGOW_HASKELL__ < 609
   -- OFun dom ran a b -> OFun dom ran b c -> OFun dom ran a c
   OFun f >>> OFun g = OFun (f >>> g)
+#endif
 
   -- OFun dom ran a a' -> OFun dom ran (a,b) (a',b)
   first (OFun f) = OFun (firstO f)
diff --git a/src/Interface/TV/Output.hs b/src/Interface/TV/Output.hs
--- a/src/Interface/TV/Output.hs
+++ b/src/Interface/TV/Output.hs
@@ -1,7 +1,4 @@
 {-# LANGUAGE GADTs, KindSignatures, MultiParamTypeClasses #-}
--- For ghc 6.6 compatibility
--- {-# OPTIONS -fglasgow-exts #-}
-
 ----------------------------------------------------------------------
 -- |
 -- Module      :  Interface.TV.Output
@@ -83,7 +80,7 @@
     Canonicalizers
 ----------------------------------------------------------}
 
--- | Dissect a pair-valued input into two inputs.  Loses outer 'oTitle's.
+-- | Dissect a function-valued output into input & output.  Loses outer 'oTitle's.
 -- Must be a (possibly titled) pair-style input.
 asOLambda :: Output src snk (a->b) -> (Input src a, Output src snk b)
 asOLambda (OLambda a b) = (a,b)
diff --git a/src/Interface/TV/Tangible.hs b/src/Interface/TV/Tangible.hs
--- a/src/Interface/TV/Tangible.hs
+++ b/src/Interface/TV/Tangible.hs
@@ -1,7 +1,4 @@
 {-# LANGUAGE Rank2Types, TypeOperators #-}
--- For ghc 6.6 compatibility
--- {-# OPTIONS -fglasgow-exts #-}
-
 ----------------------------------------------------------------------
 -- |
 -- Module      :  Interface.TV.Tangible