Asz, the 14.xx series of drivers don't really work well w/the TNT series of cards. At least this is what I've been told. They are best suited to the GEForce series of cards, from the GEForce all the way to the GEForce 3. That is probably why your TNT2 card doesen't do so well w/them. Give the 12.90 drivers a try. I've heard that they work quite well w/the TNT2 cards. Best of luck.
sincerely,
sx/amiga