[Haskell] GHC Error question

[Simon Peyton-Jones]

| What Claus says.  What is the real type that ghc infers?

It's this:
        forall a b . C a b => a -> a

| If it's really what it claims it to be, then this is definitely a bug.
| And it might not be common to you, but I have several places in my
| code base where I have to leave off type signatures, because the
| inferred signature is not accepted.

I'd love to see those examples.  Can you extract them?  You could add them to
http://hackage.haskell.org/trac/ghc/ticket/1050

Simon