Sounds like it could be a scaling issue, or maybe the Vista fix might not have been installed correctly.
Try downloading and installing the improved movies.
It's a huge download, in 6 parts, so make sure you back it up somewhere. There's also an
improved music patch that isn't nearly as big.
Put the files you downloaded into the game folder and run the executables. I always set any .exe having to do with these games to run in XP SP2 compatibility mode as an administrator just to be safe. After they're done installing, you can delete them.