Oops [Fwd: Re: Allowing duplicate instances in GHC 6.4]

Sorry, this is the compiler error I get: No instances for (KeyHasValue MyKeyVal k' v', Datasource.Tools.FakePrelude.TypeEq Float k' z, Datasource' z [MyKeyVal] [MyKeyVal] Float Int) When I am trying to do do { createJoinedDS' x x; (joined,(v::Maybe Int)) <- _dsread joined (2.0::Float); } Robert