Dude I hav eno idea what you did but it sound like you messed up your firefox on both of your machines. As I'm being nice and checking all three (yes 3!) that have ubutnu. My destop (8.10) is fine, my laptop (8.04.1) fine, my older laptop (8.04 Xubuntu) Just Fine....So this issue has to be on your end not Ubuntu's!!!
I have no issue using Facebook, even the messager works perfectly from within the browser. Im using a completly up-to-date version of 8.10
As for Hotmal - I don't use it. I use the supplied account from my ISP (Optimum Online) and a yahoo account as a back up, both work from their websites and Thunderbird(Optonline), so I can't complain. Heck fo some poop and giggle I just tried my AIM mail account and that works too...
My suggestion is you use a more user friendly email client. Oh and reinstall Firefox!