Sorry to hear this didn’t help. There must be something environmental specific to your machine that is causing the problem. GroupWise does use a number of shared Windows resources, and one of these might be the problem. I can only think to suggest that you try another machine if at all possible.
Not having any other reports of this nature, and not being able to reproduce the problem here makes it very difficult to map out a support path. Let us know how you proceed. We may need to organize a remote WebEx support session.