Groupwise 6 on W2K

I had a user upgrade her computer from Windows98 to Windows2000. Groupwise 6.0 did not work. I installed Windows Messaging for NT. Groupwise now works, but a message window pop ups stating that GWSYNC.EXE has generated errors and wiil be closed.If you close that window, Groupwise seems to work fine. I still would like to resolve this problem.