Ok, kinda a weird one here...
When I load up Arcanum in a non-fullscreen mode (the way I prefer to play, y'know, with a UI I mean) if I hit the arrow buttons to scroll around the map everything becomes garbled and I can only clearly see tiles with animation in them.
I have the official patch, the unofficial patch and the Extras. (I also have the 1024x768 patch but it doesn't matter whether I use it or not)
So yeah, if anyone has seen this before and has any leads on fixing it, I'd be appreciative.