Xbox 360 &WRT55ag drops my connection! Please help...

Question

My dilema, when playing a game over xbox live through my router randomly my router disconnects and reboots.  It does not matter if i am hosting a game or not but ofcourse when hosting it is much more likely.
My specs.
Router WRT55AG ver 2 (microsoft recommended firmware)
ISP - Comcast
I connect wired through port 1.  There is one lap top that connects wireless.
Basicly when playing at least 1 out of 4 games or more frequently with out lag or warning i get disconnected from the game.  The router losses all lights active lights then ALL lights turn on together then back off once or twice.  Shortly after that the router reboots byitself like there was a power outage and i regain my connection once i sign back in.
please give me some help and advice as both my isp and comcast have pretty much passed the buck.

Answer 1

Access setup page of router ......
Please click on the tab "Application and gaming" and click on sub
tab "Port range forwarding"
1) On the first line in Application box type in "Xbox", in start box
type in 88, in end box type in 88, in protocol keep it both, in ip
address type in 192.168.1.20 and give a check mark on enable box.
2)   On the second line in Application box type in "Xbox", in start box
type in 3074, in end box type in 3074, in protocol keep it both, in ip
address type in 192.168.1.20 and give a check mark on enable box.
3) Now save the settings
4) Once you return to the setup page, click on the tab "Administration"
and disable the UPNP and save the settings.
5) Now assign the given ip address on your xbox
   ip address :- 192.168.1.20
   subnet mask :- 255.255.255.0
   default gateway :- 192.168.1.1
Please assign the dns address on the xbox
  primary dns :- 4.2.2.2
  secondary dns :- 192.168.1.1
6) Please try to test your xbox live.