Well, it took me all this time to figure this out - and to fix it. Here's the links:
The error left very few traces on the system - no dump files, and no specific information in the Event Viewer. BUT, sorting the errors in Event Viewer by date showed me at least 5 errors installing this update just prior to the NTFS errors that caused the crash (yet there were no previous NTFS errors).
I was suspecting the SATA/RAID drivers, and tried replacing them without success. I wasn't able to boot into Vista in normal or SafeMode without the error - but setting the mobo back to "failsafe" values and several attempts at a restore finally let me back in.
The culprit was KB925902 - does this look familiar?:
QUOTE
application_executable_name - Illegal System DLL Relocation
The system DLL user32.dll was relocated in memory. The application will not run properly. The relocation occurred because the DLL C:\Windows\System32\Hhctrl.ocx occupied an address range reserved for Windows system DLLs. The vendor supplying the DLL should be contacted for a new DLL.
Yes, I do have RealTeck audio built into the mobo!

As usual, sending the report to MS didn't give me any results either - so for now that update will remain uninstalled! I'm thinking of disabling the sound until I get around to getting a new sound card. Anyone know a good one that has Vista drivers?
The cause:
http://www.microsoft.com/downloads/details...;displaylang=enThe KB Article:
http://support.microsoft.com/kb/KB925902