Well, it's working fine. compiled the NVIDIA kernel driver, reinstated a backup copy of my XF86Config-4.
At first it kept crashing out, but this turned out to be because the RedHat setup had added a line to my modules.conf:
"alias usb-controller usb-ohci"
Which disabled my uhci, which disabled my usb keyboard and mouse. Plugged in PS/2 keyboard, commented out offending line, rebooted, WOW!!!.
If in doubt, check the obvious!!