I suppose it depends on exactly containers 0.2.0.1 currently? The version coming with GHC 6.12 is 0.3.0.0.
$ cabal install wx
Preprocessing library containers-0.2.0.1...
Could not find module `Data.Data':
It is a member of the hidden package `base'.
Perhaps you need to add `base' to the build-depends in your .cabal file.
Use -v to see a list of the files searched for.
cabal: Error: some packages failed to install:
containers-0.2.0.1 failed during the building phase. The exception was:
wx-0.12.1.2 depends on containers-0.2.0.1 which failed to install.
wxcore-0.12.1.2 depends on containers-0.2.0.1 which failed to install.
wxdirect-0.12.1.1 depends on containers-0.2.0.1 which failed to install.