Vista SP1 and new ATI drivers "9-2_vista32_dd_75976" crash SL reproducible (at least my ATI Radeon 4670).
Symptom:
SL crashes on startup or during login process or while you start typing your password.
No graphic setting (VBO on/off, Antialising etc) really produced a stable state.
Current Solution:
Reverting to the older drivers of 12/2008 (8-12_vista32_dd_72275) works.
Other people are reporting the same problem, for example here: http://forums.secondlife.com/showthread.php?t=308544
I have added your comments to the main issue VWR-12139