Do you have a Google Tool Bar?
How about Google Chrome?
If not I say its the router. Many people have problems with that particular router. My friend, keeps losing internet connection on one computer.
My advice, if you think that it can be the router and it appears that it can be, since you are fine when at another location. I would try to beg or borrow a router and see how it goes. Maybe you can get one from Comcast, but then the problem may still be present.
In situations like this no one really knows. Even if you bring it in for repairs, it will be hit and miss.
In any event, I wish you luck. If my suggestion does not work, maybe, someone with more expertise will be more helpful.