GHC 6.5 error? Illegal polymorphic or qualified type

[Rene de Visser]

Hello,

I tried to compile HAppS using the latest GHC snapshot (in compiles fine 
with 6.41).

I for example get the error

/home/rene/repos/HAppS/src/HAppS/MACID/Var.hs:23:0:
    Illegal polymorphic or qualified type: forall state event.
					   Ev state event (ref t)
    In the type signature for `newEmptyRef':
      newEmptyRef :: (Monoid t, Ref ref) => AnyEv (ref t)

Note that AnyEv is defined as

type AnyEv a = forall state event. Ev state event a

This should be OK shouldn't it? At least in works in 6.41 and everythis is 
quantified.

Exactly what does the error message Illegal polymorphic or qualified type 
mean?

Rene.