[Haskell-cafe] WXHaskell problem

I just installed WXHaskell via Cabal and tried one of the examples BouncingBalls.hs. But every time I run it I get this error message in a dialog saying: "assert "m_dynamicEvents" failed in SearchDynamicEventTable(): caller should check that we have dynamic events" It also asks me if I want to stop the program or suppress further warnings. And if I press Cancel in the dialog to suppress further warnings the BouncingBalls-program seems to work just fine. How can i make this warning message go away?