Just to be clear, I don't think the problem is system update. The problem is Lenovo drivers. This is not the first time they have broken something and/or been worse than what they replaced.
I like the concept of system update and may actually re-install it. But from now on I think I'll do updates one at a time so I can easily identify the cause of any new issues.
Anyone else had their idle CPU usage go to around 50% after installing the latest grafics drivers? The culprit was (if memory serves) "igfxdrvr.exe" which I think is a driver for the video card in my x61s. System update installed it.
FWIW, I still love Vista. It has been totally solid for me, including SP2. I never thought I'd say that

But at least on the X61s it is as fast as XP, and things like networking are quite noticeably faster and more solid. I watch recorded TV shows on it, streamed from another PC over 802.11g. On XP I could do it but any significant other network traffic would cause stuttering. On Vista, it is 100% solid no matter what. I can even watch streaming video while doing a speed check.
Paul