WinHugs: Error messages stays forever

L.S.,

After giving the commands:
   :l Monad
   :a Monad
the message:
   ERROR "C:\PROGRAM FILES\HUGS98/libraries\Monad.hs" - Module "Monad"  
already loaded
repeats at every expression I want to have evaluated:
   putStrLn "Festina lente"
results in
   ERROR "C:\PROGRAM FILES\HUGS98/libraries\Monad.hs" - Module "Monad"  
already loaded

System: Windows 98
Hugs version: Nov 2003

Best regards,
Henk-Jan van Tuyl