I had huge problems with SpySweeper. Practically every event I ever experienced was false and (like most of these apps) they inflate their hit rate by including thousands upon thousands of totally harmless cookies in their threat count.

Add to that SpySweeper is a real resource hog causing incredibly long start up and a huge performance hit when it is running in active mode.

I never tried their AV solution but I did opt to lose nearly a years worth of subscription last time I had it installed because it caused so many annoying issues.

Last August, I was at my nephews place, and their PC was infected with some kind of virus/spyware.  They had an antivirus installed, a firewall + an antispyware, all were unable to get rid of it.  As soon as I killed the virus task, another one started and rewrote a different entry in the registry to relaunch itself after reboot.

I used autoruns / process explorer from sysinternals but it didn't work.

Finally, I removed their AV+Antispyware (cannot remember which brand it was) and I installed CA Internet Security Suite 2007.  It stopped the active virus task immediately after installation, and after reboot, it was gone, after removing/quarantining a large number of infected files, fortunately all non essential to the system (it was probably more a spyware than a virus).  I know CA AV is generally ill-considered by many observers/reviewers.  This time it really helped.