Xbox Live Problem Options

[Z3ROSUG4R]

Hi, i've had xbox live for 2 years and i've been using wireless for those 2 years.
I have never had a problem like this before, yes ive had the occasional lag but nothing like this. This happened 1 month ago and somehow I fixed it but i dont know how at all. It just worked again all of a sudden... so here goes.

The problem is that during the first half of a Fifa 10 game i disconnect from the game and ea servers. I remain in my parties and on xbox live but i just disconnect from ea servers. I can immediately reconnect and try again but the same thing happens. If i go on Cod4 for example all that will happen is I join a game.. im on a full bar connection everythings fine and everyone else will time out. This has never happened or been a problem before.

My Settings:
My NAT is Open
I use a Belkin F5D7230-4
Connection Type: Dynamic
Ive tried Portforwarding and the problem is still the same
Wireless Channel: 6
I have a WPA with an encryption technique of TKIP
My DMZ ip is the exact same as my Xbox IP
DDNS Service: Disabled.

Like i've said before, I've tried opening ports and the problem remains the same. This happened before and all of a sudden the next day it was fixed cause i mucked around with my router settings. Before this nothing happened.
I'm not considering buying a new router or network adapter or contacting my internet provider as i know that my problem can be fixed without this as I have done before.
I would like to know whats causing this and most importantly how to fix this! Thankyou for reading and hope you can help.

[x Yo1nK x]

EA could possibly have shut down servers for FIFA 10