Mine does thwe same thing. But I live in an apartment building. Some of the residents hook themsellves up to my cable tv and also the internet an mine goes down to 10 or 12 download. It is no use calling comcast they have never ever done nothing to stop this. It is cheaper for them to lose the customer then bring charges against the people who gain unaurthorized access. Not to mention when they are on the internet they are usaing my id , ip address , street address ,etc. I just unpllug everything for a few hours then i get a couple of hours usage from the 180 dollars a month I pay.
Post the requested info from here;