There are several threads in the forums about "Procedure Entry Point" errors. They typically occur after a workstation's GroupWise client has been upgraded from GroupWise 7 to GroupWise 8. These errors often manifest themselves when starting GroupWise or when opening new message, though they can come up in other places.
The problem seems related to the change in default directory. The GW8 client, by default, installs in C:\Program Files\Novell\GroupWise. The GroupWise 7 client's default install directory is C:\Novell\GroupWise. This presents the possibility of valid GroupWise files being present in both locations. If the GW8 client is calling GW7 DLLs, it's not difficult to see the problems that can develop. That seems to be the case here.
I suggest starting by removing the current GroupWise 8 client. Use the standard Add/Remove Programs Control Panel to get rid of it. Then use a third party uninstaller. I like the one from Messaging Architects called CleanIt, particularly because it wipes the Windows Messaging profile. And it's free. It can be obtained here:
Next, check that C:\Program Files\Novell\GroupWise is gone. If it's still there, delete or rename it. Do the same for C:\Novell\GroupWise.
Check for shortcuts on the desktop and in the Quick Launch area. Delete any you find. Also check in the Program menu, particularly for the Notify shortcut in the Startup group. Delete any of these you may find.
If ZENworks is in use, check to make sure that a GroupWise 7 install is not being pushed to the user experiencing the problem. This will complicate the problem by replacing the GroupWise 7 client after it's been removed. Uncheck Force Run or simply disassociate the application object from the user.
The final step is to install the GroupWise 8 client. The PC should be free of old references to the GroupWise 7 client and associated DLLs and, therefore, the "Procedure Entry Point" errors should not come back.