We haven’t had any report about this issue. Looks like the problem could be environmental to your machine as it works on another machine.
Just a recommendation, you are running GroupWise client “7.0.1 13/06/2006” and we was told by the Novell that GroupWise 7 IR1 (prior to 14/12/2006 build) had some bugs in relation to the OnOpen and some other events. May be you can upgrade the GroupWise client to the latest release then test your solution.
Let us know if you have any questions.