What could be machine specific when nothing has changed on the machine except the card? I've played SC games, including breakthrough, on this machine for years. Besides there have been two other documented cases, one on these forums and one on the AMD forums, so it has to be something with the drivers or card.
In any event it looks like I may have to just uninstall from my machine and reinstall on my laptop since there doesn't seem to be a solution.
Thanks for your help regardless.