[kh99]

I see. Well, I'm afraid I'm not sure what you can do (which doesn't mean there's no way around it, only that I don't know). I think there may be no choice but to change the id or do without the version check (or implement your own check url on your server, and return the productid you're using).

Edit: ..or write install code that copies any data that you need from the 'other' product. I'm assuming there's data and/or settings you're concerned about, or of course you could just ask users to uninstall the old version.