Comment 4 for bug 338631

http://www.septitech.com/ does not crash here with no extensions/addons installed just plugins. please check if a new profile helps and see if removeing all extensions help (you might to try firefox --safe-mode to test)

Same for http://www.huffingtonpost.com/2009/03/05/jon-stewart-eviscerates-c_n_172057.html

It looks like both links have alot of pics and friends that makes it load slowly.
Please check the things above.