I just put in a Nvidia Geforce gtx 560 ti, and now my game is acting very strangely. I'm doing a lot in Edit Town, and for the first 5 minutes or so, everything is amazing. After that, when I try to use CASt on objects or change the camera angle, everything slows to a crawl, and freezes periodically, and the cursor jumps around and doesn't move smoothly.
Anyone have any ideas about what's going on and what I should do?