Another bug in an update? (Score 1)

As some of you may or may not know (not that it matters) I work support for a major OEM that ships systems with... you guessed it, Windows. It looks like one of these updates just might have a problem. We've seen a few XP users call tonight with an issue stemming from "Update 1 of 3." This is the last update that installs before the system reboots and starts coming back up to a screen that says the system needs to reboot. Anybody else having issues with this? I managed to fix one with Last Known Good Config but I'd still like to know which one caused it.