Hello, I have the following code which works ok on Linux and Windows XP, but fails on Mac OS X with error message: Connect: does not exist (connection refused) The server: doStartstate = do pr <- liftIO $ runProcess ... liftIO $ threadDelay 500000 st <- get put st { slimHandle = Just pr } The client: fetchAnswers st msgs = liftIO $! do let port = PortNumber $ fromInteger $ port $ config st cnx <- connectTo "localhost" port Help most welcome, thanks Arnaud