Trend Micro offers a free online spyware scan at http://www.trendmicro.com/spyware-scan/ and an online virus scan at http://www.trendmicro.com/hc_intro/default.asp

I have their PcCillin and a varmit got past it (it's like a guy said about birth control...if it's 99% effective the numbers will get you every time).  Their recommendation was basically I uninstall my firewall and anti-virus, use their online free scans, then reinstall fresh.  So far it seems to be working .