I am encountering the same problem, that the new 4349 driver hard crashed my RedHat 8.0 with lastest 2.4.18-27.8.0smp upgrade. The non-smp version works just fine.
My configuration is Ti 4800 (actually, a 4600, but with 4800 chip ID), dual PIII, 440BX, and I only have a flat panel display which is connected to the DVI output of the card. I have the "ConnectedMonitor" "DFT" setting in the XF86Config file.
It crashes disregard I set or unset either one of the following options: