The only thing I can think of is that your appearance.2da file has been kept the same unknowingly in your compatibility file, while the one in your main directory is updated (a problem with Windows vista and 7)
Try opening your compatibility folder and dragging the appearance.2da file to the desktop (don't delete it as you may need it)
You can locate the compatibility folder here
http://imageshack.us/f/215/51512434.jpg/
FYI, I'm not sure if this is the problem, I just think it could be as windows 7 has known to make duplicate appearance.2da files, yet only updates one, which makes them conflict with eachother.