Avast 4.7 affect battle net games?

Hi guys, i have the above problem.

Computer has been running fine for a while now while playing warcraft III on battlenet, including hosting games and playing other people games, both ladder and custom. Lately though, without much change to the computer i have been randomly but recurringly gettin dropped from games, both ladder and custom, at around the 5-10-15 minute interval. (never get a full game). Considering nothing much has changed is there a setting in avast which might be causing this ? (during an update or something?). Am only running the xp pro sp2 firewall with the home edition of avast 4**.

Regards,
Nam