Here are some things I feel you need to know:
NAT is open.
All ports forwarded.
Tried power cycling.
Connection is wired into my Linksys WRT160N router with an undamaged Ethernet cable.
My connection speed is the following: http://www.speedtest.net/result/1420661412.png
Whenever I play games, all my actions are delayed. In Halo Reach, if I toss a grenade, the grenade doesn't actually toss until about a second after. Same with meleeing someone. If I melee someone, they don't get hit until 1-2 seconds after the animation, and it really screws up my games. What can I possibly do? I have my laptop on the net while playing xbox live btw.