[Haskell] Garbage collection problem

HI,can anybody help me with the following garbage collection problem ? I'm trying to develop a test tool which can generate test data systematically for Haskell program, I have finished most of the work so far, however,while testing, the process would be interrupted because of the garbage collection problem with the notice "ERROR - Garbage collection fails to reclaim sufficient space",what shall i do to solve this problem? so that the user may test the possible input of a infinite type all the time as long as he or she wants to. By the way, the interpreter I used was Hugs98. Thank you very much. Best regards Jinping Zhang