Hi puchero,
Have you tried a boot time scan with avast!? Right click the scanner screen, select ‘schedule a boot time scan’ and reboot when requested.
Try AVG Anti-spyware:
http://www.ewido.net/en/product/
And maybe a few online scans if you can get them to run:
http://support.f-secure.com/enu/home/ols.shtml
http://www.bitdefender.com/scan8/ie.html
http://www.pandasoftware.com/products/ActiveScan.htm
(Disable avast! before running online scans.)