Firefox "page cannot be found" errors ALWAYS

Hi all, I'm wondering if someone can tell me wtf is up with my system. I keep getting (instantly) the default couldn't connect to server message when viewing pages in Firefox. It's not certain pages, and it's not all pages at once...it's here and there and random, sometimes worse than others but that doesn't seem connected to what page I'm trying to access at all. I refresh sometimes once, sometimes 5 times and eventually it comes up, though sometimes it loads funky, like without images, or as though I have the nopage style option enabled (which I don't).

I'm using 2.0.0.14, but I had this issue even before the last upgrade.

My Add-Ons are:

Adblock Plus

Greasemonkey (only one script installed...the one to auto-refresh your MySpace homepage)

ForecastFox

Distrust

RefControl

User Agent Switcher

Download Statusbar

External IP

I've tried disabling the Windows firewall and my AV (Kaspersky) but it doesn't seem to change anything.

My system is WinXP SP2 on an AMD 64 X2 6000+ with 2 gigs of RAM. However, my install is a hacked XP..one of the Lite versions that removed a lot of unnecessary crap. Setting my services back to default doesnt seem to help, though.

Anyone have an idea? This is driving me nuts. Oh,and it DOES seem to happen more often when I'm downloading a bunch of stuff (like on Bittorent, etc) than otherwise. No lag when it's trying to find the page...just immediately can't find the server.

http://www.speedtest.net/result/198684809.png (speed test)