Extensive troubles w. Connection/SNF while browsing errors

I am having quite a lot of trouble with trying to narrow down what is causing the issue. In a nutshell, I will be browsing (and this will happen with any internet browser it seems) and sparatically I will receive "Connection has timed out" or "Server not found". This is particularly true when I power-on and load Firefox and a handful of the webpages from the previous session. It will take 2-3 minutes of hitting the reload/refresh button before the activity kicks up and I can start my session. However, after my browser has loaded, I will get these errors in seemingly no pattern at all and the outage usually lasts around 1 minute.
The kicker: I have been able to systematically cross out that it cant be the cabling Im using, either of the routers, or the DSL modem because the other computer in the house does not have this issue.
I dont feel the problem is within the actual connection. I havent noticed any connection drops through Ventrilo, Mumble, streaming WinAMP or Windows Media player, no drops according to my bandwidth monitor (courtesy of NetSpeedMonitor) and flat-out no connection troubles seen on my Internet access controller on my taskbar.
I have had this problem for about a year, but it has finally gotten to me where I just cant take it anymore (especially with school and taking online courses!)
I have tried switching auto-detect proxy settings, DNS flush, Ive tried switching the types of networks used (Home,Work,Public), I had moderate success with getting rid of my Anti-virus program, and I've googled just about every combination of "Connection has timed out, Server not found, DNS, windows 7, firefox, and IE" that you can think of without much luck. I feel that maybe the problem might be located in the Registry.
For the sake of science, education, and just-getting-to-know-Windows7-better, does anyone have any clue what I can do? Im praying to the computer gods here.

Anyone?