...extremely long delays in powering down and starting up. Many machines get stuck at the "Shutting Down" prompt upon shutdown and again at the "Windows is installing updates" screen upon startup. A hard reboot is required to get the computer to completely power down and the startup can take upwards of 45 minutes to complete. Once complete, mouse movements are jumpy and performance is sluggish. Booting into safe mode appears to resolve the problem, but booting back into normal mode brings it back (this was my behavior though others have seen slightly different behaviors here).

After fighting with this one overnight, I called in a case with Microsoft. Because this is a patch-related problem, cases like these are what Microsoft calls "non-dec", meaning that they will not count against your available cases and/or will be of zero cost to resolve. In working with the engineer on the phone, it was recommended that I attempt to hide the update from within the Windows Update Control Panel. Then, I was instructed to download and manually install the correct patch from this web site: http://support.microsoft.com/kb/943899.

According to the engineer, the problem is related to something within the original patch code that causes the problem on some machines. 64-bit Vista machines appear to be those affected the most, and the problem may lie exclusively with 64-bit machines only (yet to be determined).

After applying the patch and rebooting once or twice, the problem appeared to be resolved. I've seen only a few reports on this issue on the net, so the problem appears not to be widespread (likely due to the non-widespreadedness of 64-bit Vista).

Are you seeing this problem? Have you found other fixes? Let us know...