Routers have a known issue with hosting and using some applications with a router especially if you use PPPoE (sp?) and it will drop the connection, I have not figured out why yet and i havent found a sulotion on the net either, havent been looking too long for it either though so there might be a solution to it but I'm not aware of one and if you do find one please post it
A nice fix for this, the only one i know is to have a seperate modem an unplugg the router temporarly and plugg the modem directly to the computer instead, have never had this issue with that setup so its defenetly the router thats the problem in my case atleast (and it doesnt matter what router you have, as a person with a Linksys router and cable/fiber will have no problem but a person with a Linksys router and ADSL will have a problem, like me). This will not happen on a cable or fiber connection.
Sorry can't help you, hope someone in the world knows a fix to this.