Unfortunatly, the newest det driver will screw up any tnt/tnt2 card. However, I have found these sky problems happen with the default winxp drivers for tnt2. Try 12.?? nvidia drivers to correct this problem, its not a bug in jabo 1.5.
Edit: Ok, just read the win me. Still try 12.xx if you are having problems... its a driver issue at any rate.