Ok, now it's ur video card/ monitor problem.
What does ur video card detected as in Red Hat 9?
During my early days when i use Red Hat 7.X, i do face problem in such case. Please check ur
1) Video card driver u chosen (not really the problem i suspect)
2) Ur monitor (i suspect is this the one causing the problem) - Check the refresh rate and resolution u use. Just dont fry u monitor
One more thing, Red Hat doesnt like new video cards. So better get one driver from nvidia's site.