Thanks Tiggi! Followed your instructions and it finally worked for me. I think the you are right. The key is to search and delete all the RigExchange.db files, not just the one in the main program folder.
I'm having the same issues, except with Windows 7. I've tried rebooting several times, removing the program through the program itself and from the control panel (including several prior versions), and removing .RigExchange.db from the program file. Nothing has worked thus far. Thanks.