You can also run the ICE PIMP client to do the job of re-setting your credentials (essentially what you're doing by reinstalling the software) - you don't have to use the other features of it. It can munch a bit of RAM though.
Justin
Edit: I should add, PIMP can be set to "reset" the ID to the correct one on a daily basis - handy if you do auto Windows updates. If your Windows updates are downloaded & installed @ 3AM, you can set the guide ID to check & reset itself @ 4AM in case the updates have stuffed things. If your scheduled guide update then happens at 1PM, you should never run in to the "sample data" issue.