HotFix causes Thinkpad to fail to boot off of battery power

I had a user at my company complain that their Thinkpad R51 would freeze
during Windows XP booting. Turns out they had installed the Microsoft update
mentioned in KnowledgeBase Article 885894.

I had just received a new Thinkpad R51 from Lenovo. So to test, I did the
following on this other Thinkpad R51:

1) Installed Windows XP Service Pack 2
2) Installed the latest ThinkPad "software installer" for this model
Thinkpad from www.ibm.com, and used it to download and install all the newest
IBM drivers, firmware and utilities. Restarted.
3) Tested that the Thinkpad booted under battery power (it did fine).
4) Reconnected A/C power, then installed the Microsoft 885894 update.
Restarted (booted fine).
5) Shut down, then unplugged the A/C power & restarted under battery power.
The ThinkPad froze while loading Windows XP. It never made it to the login
screen.

Please let me know if there is an incompatibility between Microsoft's 885894
update and the latest IBM Thinkpad drivers or firmware.

Reference: http://support.microsoft.com/default...b;en-us;885894