I also have severe lag but haven't gotten any help with my prob either 
Hopefully someone will get back to either of us very soon on this. I would post COH Helper info and HijackThis info on here for a quicker reply.
I have read a few posts like this. I believe a repair operation has fixed some of this for others.
Another question, are you using compatibility mode within vista or 7?
Thanks Zep, that worked perfectly, after the repair it ran perfect.
"Yes, winning all the time can be boring."
-Knight_Chill
"It's amazing how well you can put up with endurance issues if you hide them under a large enough pile of bodies."
-Spiritchaser speaking on Dom Revamp
This is a recent issue, but I am having some horrid lag issues. Running on the the game on the same computer for the past year (On Ultra) and now for some reason on live a lot of NPCs are laggy and using different weapons (Fallen Buckshot pulled out a Nem rifle) and my toon does some crazy animations (When I throw a fireball I will do the Whirlwind animation.)
Can anyone give me any help, I will post Hardware info if needed, but like I said, I have been running it for a year.
"Yes, winning all the time can be boring."
-Knight_Chill
"It's amazing how well you can put up with endurance issues if you hide them under a large enough pile of bodies."
-Spiritchaser speaking on Dom Revamp