Each time I ran Xconfigurator, it would fail at the "test your settings stage" with an unspecified error. The settings it chose were 1600x1200x32, but I tried manually setting up other modes such as 1152x864 and 1024x768 but they didn't work either. When I booted to the fisher installation, I edited XF86Config-4 and X worked first time. GeForce2 GTS card, Athlon 800, Ka7-100
We (Red Hat) should really try hard to fix this before next release.
Need to get a GeForce to debug this.
*** This bug has been marked as a duplicate of 21500 ***