KB941649 problem

To put this as shortly as possible...

Windows Vista and Performance: Yuck!
A month ago: Microsoft to release updates that improve performance! YAAAAAAAY!
I was so enthusiastic that I downloaded KB941649 off the site the day it
went public. Then... BOOM!

You must restart blah bhal blah... so I click restart now. Aaand windows is
shutting down... ... ...windows is configuring updates... ... ... ... ...*45
minutes later* windows is shutting down... ... ...*one hour later* windows is
shutting down...

I push the restart button. I log onto windows. And I start experiencing
weird errors and crippled functionality. System Restore WOULD NOT START UP.
Scanning disks........ *nothing*

I pop the Vista DVD in and do a System Restore with its repair capabilities.
IT WORKS YAAAY Windows is back to its old self!

I try a reinstall of the patch... SAME SCENARIO.

Today: Patch Tuesday
News article: Microsoft releases KB941649 which will improve performance on
all Vista machines YO HAPPY DAY!
Me: .......*jawdrop* Oh dear... *I go to quickly switch Auto Updates to OFF*

....is this patch the same version as the one that screwed up my computer?
I've ran out of free tech support and I DON'T wanna spend money on the
phoooone plus this is a 1337 update, will someone PLEASE help me troubleshoot
my problem?

Nevermind I worked up the backbone to try and install it and it worked like a
charm. Once I got into windows however, I got that horrid error I got on my
previous attempts - a balloon telling me could not connect to the event
viewer then a popup telling me my license info was changed and I need to
reboot or windows will stop functioning?! WTF! o.=.O Aaaanyways everything in
Windows worked fine unlike last time, and after I rebooted I got no more
errors or stuff, I checked my Windows license in properties it's still valid.
Yaaay! Glory glory glory!