kirathe5th: I'm having a similar issue on my end. Everything works fine up to the opening cinematic. After that, though, the screen goes black except for a small square in the top left corner of the screen, and stays that way until either I force it down or it crashes. The weird thing is that the game worked fine for the first hour or two that I played it. I minimized out of full screen to take a Skype call and when I pulled it back up again, the screen was black, I had to shut it down, and it wouldn't work correctly when I booted it up again.
I've tried reinstalling the DirectX package in the troubleshooting guide, my drivers are up to date (or they should be, given the game worked fine before) and I've even tried uninstalling and reinstalling the game, with no success.
I have the exact same problem. When I make a fresh install with Co8, the game worked, I reached level 3 and the moathouse. Then a program running in the background forced ToEE to minimize, and now I only see the black screen with the little square on the top left.
It is very annoying, cause except for that I am enjoying the game.