Netgear gaming problem

So, after having a new netgear router (yes I know they aint the best but dad thinks they are best :S Lol) I try to go on xboxlive e.g. call of duty mw2 online and its really laggy and xbox live signs off after a minute of being ingame, This happens even on computer e.g. steam games.
Ive added all the correct ports and stuff but still having problems
the model is
Netgear DG834

Garaahhh1! help me!

Netgear are fine. My guess is the connection somewhere, either your broadband or the connection between your PCs/Consoles and the router.

The router we had before worked 110% perfectly!
but my brother went to update firmware and crashed it so we had to get a new one, Since that everything has gone boobs up :/