Got a similar problem. Using win 7 (x64) and before installing the game everything worked fine. Install GC2 and the mouse went crazy. It auto scrolls, all the time. Quit the game, it STILL auto scrolls in everything. Uninstalled the game, drivers and it still auto scrolls.This is unbelievable.
I bought GC2 3 years ago. I deleted it then after 2 weeks from the serious bug issues. I thought maybe, just maybe Stardock would have solved them - not. I'll keep working on the problem, since I need a mouse, however, the new game Elemental, which looked so good has been crossed off my list. From what I have read, it was released in a pre-beta format and is even worse than GC2. How can a company with such great ideas release such amazing games with so many bugs to make them unplayable?
added: If you uninstall the auto updater, it might help. Worked for me. It's unfortunate that even a small updating software package is full of bugs. Get with it Stardock!!!!