ok on my RIVA TNT (first generation) card,my app that uses the glTexSubImage2D function works like a dream.30+ fps with no probs. BUt after I installed my new Creative Labs GeForce2 card the frame rate dropped to about 1 or 2 frames per second!!! I though my new card was supposed to speed things up 
Any idea what causes this?
Nevermind…got it fixed. I downloaded the latest Detonator 2 drivers and that fixed my problems. 