Have you tried running with "Use Software OpenGL" option box checked? It will be slower, as it bypasses the hardware acceleration built into the FireGL card, but if the problem goes away then it definately is a Driver problem and not something else. NB.This option will be greyed-out if there is a file loaded.
Another symptom that I had with the 8.163 driver; was when I switched between open SW parts, everything except the main view pane would change to the selected part, the main view would stay showing the original part, then as I passed the mouse over tree pane, I would see pink outlines of the selected part appear superimposed onto this wrong view. If the view orientation icons were used, a pink wireframe of the "hidden part" would show through. If I minimised and restored the whole SW window, there would be a "Hole" through to the desktop where the main view pane should be. In more polite moments, I called it a view PAIN until 8.323.0.0 sorted it out. I don't know if this driver is compatible with your card but it might be in ATI's archive if it's not still listed.
Trevor Clarke. (R & D) Scientific Instruments.Somerset. UK
SW2007x64 SP3.0 Pentium P4 3.6Ghz, 4Gb Ram ATI FireGL V7100 Driver: 8.323.0.0
SW2007x32 SP4.0 Pentium P4 3.6Ghz, 2Gb Ram NVIDIA Quadro FX 500 Driver: 6.14.10.7756