Not only Chiko's laptop is having major problems with XP SP2. It seems mine is now getting a bluescreen error in arp1394.sys (firewire driver) every time I suspend it. I've been doing a lot of overnight compiling and downloading (latest Debian DVD's which took about 3 days to download) lately, so it took me a while to notice this. Two out of two computers with major problems after installing SP2. Just how much testing did Microsoft put this through? I'm thinking of sending them an invoice for the time I've wasted so far getting Chiko's PC back into a usable state.
Update 3/10/2004: As noted in the comments, the cause of the problem turned out to be Kerio Personal Firewall 4.1.0, which I'd upgraded to shortly after installing SP2. If you've found this page through Google because you are having the same problem, and have Kerio installed, try upgrading to 4.1.1 (or later if a newer version has come out by the time you read this).