Sorry to revive an old thread but I wanted to add something that may be helpful.
As I said above my laptop had no bandwidth issues on ATS or anywhere else but my sons desktop was having problems.
I initially thought that it was only during the game World of Warcraft but after weeks of hearing him whine about the lag I decided to get on it and
see what was up, it turned out that it lagged everywhere else to but he only noticed on his game.
I performed a speed test and the result was about 3000 down and 128 or so up, which is about 1/3 of what I get on my laptop.
I'm a former network engineer but this thing had me stumped for the last couple of days, I knew that it was a virus but none of the virus appz I
tried could pinpoint my problem.
Finally I stumbled on a post in a forum that gave the name of a AV program that I had never heard of before, so with nothing to lose, I found it and
downloaded it.
The programs name is AVAST and after running it and rebooting I performed a speed test, this is the results..
Last Result:
Download Speed: 10474 kbps (1309.3 KB/sec transfer rate)
Upload Speed: 1031 kbps (128.9 KB/sec transfer rate)
The program comes out of the Czech Republic, which made me a little wary at first

lol j/k
You can dl it at Cnet, the home edition gives you a 60 day demo but if you like it, keys arent hard to find..
Avast
hope it helps