100% CPU w/ Automatic Updates enabled XP PRO SP2

Sometimes on reboot, if Automatic Updates are enabled, when the
computer boots wuauclt.exe (the windows update client) will take 100%
cpu usage and nearly hang the computer, making it run slow as can be.
If Automatic Updates are disabled, this does not happen. I'm not sure
if it is related, but I am also having a strange printer problem;
sometimes when printing my computer spits out an error and says it
cannot find my USB Epson Stylus 900. However, sometimes if I close my
explorer windows it will say "a printing error has occured" and it
will start printing. Also if I reboot, it will almost always start
printing fine again. I have also received the "Your computer has
recovered from a serious error" a number of times recently when
rebooting (I leave the computer on 24/7).

Despite all this, for the most part the computer works fine, even with
intensive 3D video games. Also, a good portion of the time Automatic
Updates works fine. Yesterday I had automatic updates on, and
received an update with it running no problem. Later I had to reboot
after getting the USB Printer Error and wuauclt.exe was taking up 100%
CPU upon restart. When it does this, sometimes if I disable all the
processes and start them up again it starts working okay again.

I have scanned my computer with the following:
CA's E-Trust Antivirus latest
Trend Micro online AV scan
Swat-It Trojan Scanner
Ad-Aware SE latest
Spybot S&D latest
BHODemon

And I've come up with no virus/spyware

I've also used the following:
Hijackthis latest
Taskinfo 2003 latest

To identify every process running, and have found no malicious
processes running. I also have Zonealarm running and found nothing
suspicious in its log or in the program list.

I've also Scandisk'd and Defrag'd my harddrive, and used the windows
tool to verify all my critical system files are intact. Also used
memory testing and harddrive testing software and found no errors. I
checked through the admin event logs and couldn't find any clues as to
what was causing the errors.

That being the case, the 100% CPU usage with Automatic Updates on boot
does not appear to be a virus/worm, as I have exhausted every resource
and have failed to identify any such problem. However if it is not,
what could this strange problem be? And where does the issue with the
printer fit in and the "recovered from a serious error" issue fit in?
Is there anyway to fix this without reinstalling windows (or disabling
automatic updates )?