Regardless of what virus program you run, it misses a lot of the "little stuff" (especially if it's the basic.) I use Lava soft's ad-aware, a free program that grabs and quarantines and allows you to view and anihilate them after a scan.

You may need to clear your cache more often. Browsing history, cookies, etc. I have two or three places to do that, and often do all of them... PC bar has the cleaner under it's Privacy tab... and your browser has one under tools/options or such.

Just like here at PC if you go into the gallery and view pictures and then go to chat, you'll find yourself being booted out...until you clear your cache... it probably needs to be done more often with many users.

Then you also have a place on your computer to set the amount of RAM for holding all that history. Make sure you increase it according to the size of your total memory. No sense in having a limit of even 1 GB if you have a computer of 160 GB.

Others might have more info too.