Haha...well, your hardware is decked out enough that I think we can rule it out as a contributing factor.
Who is your ISP? Do you have "cable" broadband?
Do you use ethernet or Wi-Fi?
And a fresh install of Firefox will keep addons if you don't delete your previous profile. Managing profiles
. So I ask again, do you have any addons?
Give me as much info as you can, and I'll do my best to try and figure out what's wrong and how to fix it (geez, what a run-on sentence...lol).