Brand new iMac - wont load certain sites?

Hi everyone,
I'm very, very new here!
I bought a 24" Mac a couple of weeks ago. The set up was stunningly fast, and its just beautiful to work with.
But, I'm having issues loading certain websites.
Facebook, Myspace, Ebay are all having the same issues, where they take 10 minutes to load one page, and its all spread out, HTML goobledegook. That's if it will load at all!

Its horribly frustrating. Other websites fly by. What do I need to upload/download to fix this?

Any help is appreciated!

ETA: I have tried Firefox, Safari, and Flock with the same results.

Okay..

1)
2) It might be a network stop up or something along those lines..basically something (or someone) is occasionally eating your bandwidth.

3) And someone here might prove me wrong..I'm not a networking type of geek

It can also be the websites FYI...

It's probably ipv6 causing you grief. The problem is usually not the operating system but your home router or ISP. That may not be your total problem but it's worth a try to test. To disable/enable it on all interfaces open Terminal (Applications/Utilities) and type the following:

To disable:
sudo ip6 -x

To re-enable:
sudo ip6 -a

Enter your user account password when it asks. If that works, keep it disabled unless you run into problems. Many ISPs and home routers have trouble with ipv6. I also run Linux on my Macbook Pro and I noticed a big difference under Kubuntu and OS X when I disabled it. Some will notice more improvement than others.

Try this: Go to /System Preferences/Network/Advanced/DNS tab/ and change the ipv4 or ipv6 addressees to 10.0.1.1

What is that going to do except break their network connection? The IP address must match his DNS server address or resolution will fail and I'm not sure how any of us could possibly know his network settings. I'm a new Mac user so maybe I am missing something but this goes against my understanding of TCP/IP.