Several of our XP SP2 workstations (maybe 10-20%) were not able to automatically shut down and complete the reboot required to complete installing the November Microsoft security updates.  We had to walk over to them and touch the mouse to trigger completion of the shutdown process and then the machines rebooted and completed the install of updates.
Microsoft says likely cause is AV/AS conflict or bad video drivers.
We have the same video drivers we always had (these same workstations didn't have this issue in the previous months), but we did upgrade clients to RU5 last month, so it points to Endpoint.

Has anyone else noticed this problem?