Just want to let you know that we’ll be glad to provide any support from our side if it will help to figure out what is the reason of discussed issue.

Regarding ads from ad.adperium.com as possible problem - isohunt.com works with Adperium ad network as well and they display ads from ad.adperium.com too. But when browsing isohunt pages I got no any alerts from Avast while I got them browsing kat.ph.