I Have Comcast for my ISP with their provided Netgear Modem/router. I can log into the internet with the PS3 but every time I join a game to actually play the all the lights on the router go out and it resets. If a game is in progress I am able to observe it. The ps3 gives the message that the ethernet cable has been disconnected when the lights go out on the router (makes sense). I have one other computer on the network and it is idle. Has anyone else had this problem or know what the issue could be? This is the 2nd router installed by comcast and I have them coming back to change it again.

It's def a comcast issue. You should have them test your lines for static.