[Haskell-beginners] Ambigous Types with Haskell Functional Graph Library

Hey all, New to Haskell and I'm trying to use the FGL but I keep running into the same error. If I load Data.Graph.Inductive.Example and use one of the example functions such as ucycle I get: Ambiguous type variable `gr' in the constraint: `Graph gr' arising from a use of `ucycle' at <interactive>:1:0-7 Probable fix: add a type signature that fixes these type variable(s) Here's the type of ucycle for reference. ucycle :: Graph gr => Int -> gr () () I'm using GHC 6.10.1 and FGL 5.4.2.2 Thanks, Joe