Both myself and a colleague have had big trouble with the closed-source nvidia driver recently after doing "yum update". His system presents a red screen of death, and mine simply hard-hangs and locks up trying to load the kernel module (actually - the module trying to identifying the card locks the machine.). I've gone back to the stock xorg "nv" driver rather than the "nvidia" for the time being.
Has anyone else seen this recently? If so, it might lend weight to any bug report I file. Otherwise I'll just get the normal "It's an NVidia problem". Which it's not (necessarily).
(edit) I should add that I've used different kernels (from 2.6.11 to the latest 2.6.12) and different NVidia drivers (6167 to 7676, both pre-compiled via yum and installed from the .run file). Nothing works.