I have a wireless tl wr740n router and i can't play any online games without timing out from server and kicked

Things i tried to solve this but No LUCK:

1-Disable all windows and AVG firewalls

2-Used DMZ

3-Port forwarded games

4-Reset winsock(or whatever its name) and all that

What makes me go crazy that when i reset the router settings and obtain a new ip from DHCB i can play online games

BUT when i shutdown the router and try to connect the other day i can' play online games

Plz Help i'm stuck to this for a month