The problem is with the version of Xfree86 supplied with RHL 7.2
To solve the problem you need to upgrade to XFree86 4.3.0.
I know this because I tried RHl 7.3,8.0 and 9.0. And X works only in RHL 9.0 since it has Xfree86 4.3.0. You can however, get sound and other MB devices(i.e NIC) to work. The drivers can be found on
www.nvidia.com. There is an alternative to the above step. Goto
www.nvnet.com, there is a specific post to handle this very problem.