Found this when googling for a solution to my problem and registered just to replay.

For the past few days I’m experiencing the same thing with Bluesoleil and on top of that the computer frequently locking-up (explorer windows that were already opened become unresponsive, taskbar unresponsive, can’t open task manager, etc).
Reinstalled Windows XP last night, everything working fine, installed Avast and problems started reappearing. I thought it was because of version 6 so I uninstalled Avast 6 and installed Avast 5.1. SAME THING!
Don’t know what happened lately to Avast which it’s been working great for me during the past 2 years. Maybe it’s something in the virus definitions because there’s nothing else that changed from the time it actually worked… ?!

Anyway, since most of the guys over here are in denial I see no reason in living with our frustrations until somebody actually wakes up and does something to fix it. Good thing is we have alternatives.

Sad thing is that I actually liked Avast.