In this instance, GW started misbehaving like this today after an uninstall of Firefox 3.0.4 and install of the latest version [3.0.6] as well as an update of the Symantec Endpoint Protection to ver 11.0.2 and the latest NW Client--those were the only three 'updates' to this workstation yesterday that could be linked to this new behavior.
Turn off spell checking, and it's fine. Now I need to get to the root of this. However, I did want to say that for a US workstation, the registry key for the "User Word List 0" points to:
c:\documents and settings\username\Local Settings\Application Data\GroupWise\WT16US.UWL
Wondering what in those three updates (Symantec, NW Client, Firefox) began meddling with the user dictionaries?? Hmm....