i hate to be spreading this message everywhere. but why are you still running RH 8?
that is a huge problem, both for security reasons and for sanity reasons.
linux has become leaps and bounds better determining the right hardware settings for you, with no trouble at all. try an ubuntu live cd, and see if that gives you the proper display. furthermore, try ubuntu, or fedora core if you really like RH. either way the newer kernels are better, and the newer version of all of the window managers are great. and chances are, the troubles you are having just won't be there; someone has likely solved this problem, but the solution lies in using the newer tools.
and mainly, you should be doing this for security reasons. RH 8 is so far past being supported, i think they stopped rh9 support 3 + years ago. there are many known vulnerabilities that have been patched since then but only in newer and supported distributions of linux. you are seriously begging for trouble by running such an old distribution. you owe it to yourself to upgrade. really.