From time to time various anti virus makers have an update that incorrectly tags a file infected with a virus.
The quickest way to get this fixed is to report it directly to the anti virus product having the problem.
This thread will have links to various anti virus products and their report a false positive report form.
AVG -- Please login to see this link.
Norton/Symantec -- Please login to see this link.
I will update this as I research more links for reporting false positives.