I get the same thing. I never click on the message link. Go to the upper right hand corner of the home page under your user Name and you will see below it a link for Private Messages. This seems to work fine and does not bother my AV program.
Amateur Radio Operator (KE5DFR)|Full-Time! - 2012 6.7L Ford Crew Cab Dually -2013 HitchHiker Champagne 38RLRSB - Travel with one Standard Schnauzer and one small Timneh African Gray Parrot