Bit of a long story behind this one, so bear with me...

When I first got GC2, I did the full download from Stardock onto a seperate partition from the one that XP was installed on. Hence, when said windows partition died, I didn't lose my installation of GC2.

When I reinstalled windows, I could happily play GC2, even though it wasn't 'technically' installed. I quickly realised that this wouldn't work forever, though, as SDC didn't recognise the installation, ergo I could not download updates without a full reinstall.

I did so for the main game files and for the multimedia, but was a bit reluctant to go for the 700-800 mb download of the media and tutorials, so I simply copied the files that were missing in the downloaded version from the old version. It all plays fine now, and nothing seemed to be wrong for a while.

Recently, though, I noticed a bug. I use Xfire, which in the old pre-windows-reinstall version picked up GC2 fine and allowed me to chat in-game. Now, Xfire just gives me a sound to alert me when I get a message, and I have to alt-tab back to windows to see what was said. Apparently, it also fails to show me as playing it in my status.

Today, the final piece of the puzzlement fell into place. Attempting to start GC2 from the Xfire launcer spits out an error saying:

The product appears to be validated but the serial number or the machine SID don't match.

As a problem, it is both irritating and worrying, as I can't help wondering if it is a symptom of a more serious problem...

Help?