Quoted from <http://www.kessels.com/forum/index.php?topic=1436.0>

All AV software has some probability of false positives.

As confirmation, one can use online service to upload a file
and test is by multiple AV products.

e.g.: <http://www.virustotal.com/>

IF only very few of them detect malware ( and a file is not fresh new), then
there is high probability a file is OK and you should put the file to
exceptions not to report.