cache virus

Everytime i clear my cache(temporary internet files) and when finnished it shows up:

Virus Neutralized
A virus ! has been found and
access to the infected file ! has
been prevented

This has never happened before as it started about 3 days ago.
Any idea as i have scanned the computer time after time and still shows a notified vius shown but it doesnt seem to have removed the problem.
Im using

panda is 2008

Any ideas thanks.