[Haskell] Fundep broken in GHC 6.6

Hi, The following class declaration worked in GHC 6.4. I recently upgraded to 6.6 (following Debian), and now it is broken. class Error e => Game b mv e | b -> mv e where newBoard :: MonadState b m => m () ... Since MonadState has the fundep m -> b, the type of newBoard fully specifies all of the class parameters. And this worked fine in GHC 6.4. But GHC 6.6 complains: The class method `newBoard' mentions none of the type variables of the class Game b mv e When checking the class method: newBoard :: m () In the class declaration for `Game' Any ideas? Thanks, Yitz