I don't understand

SPote1522

Hello,
I'm french so excuse me for my english...
So I uninstall IE8 and install firefox, because I'm on XP and there'are a lot of problem actually... I can start the game whereas i couldn't with IE but I have another problem.
When I am on the first page ( when you press start game) I don't have the announcement , and firefox put the announcements on a new page. It's like a pop-up, and i can't log in because there are a lot of "pop-up" when I want to log in, and the loading,beetwin start game and when you log in,begin again. And if I log in in every page of cross fire ( for example when you select room) a lot of pop-up come...
I have this: http://img31.imageshack.us/img31/2372/crossfireproblem.png
If someone know why...
Thank you.