vear: Try running the game with command line parameter /NOVGARAM (just editing the game's shortcut is the quickest way).
It used to help with graphical glitches years ago, I'm not sure if it's still a solution, but it's worth giving a try.
this worked for me! thanks
for anyone puzzled what to do... i did it this way:
create a shortcut to the at.exe
open file properties of shortcut, make sure the top editable line ends like this: At.exe /NOVGARAM