[Haskell-cafe] How do I fix this error message?

Hi everyone, I ran into this error when recompiling some code I hadn't worked on in a while: Foo.hs:19:7: Could not find module `Control.Monad.Error': it was found in multiple packages: monads-fd-0.0.0.1 mtl-1.1.0.2 I gather that monads-fd is supposed to be a replacement for mtl, but I have both of them (mtl from the normal GHC 6.10.4 install, monads-fd from cabal). I don't really care which one I use, though mtl has been fine in the past. In the past, I had to manually uninstall cabal packages that used incompatible libraries. Is this still the case? TIA, Mike