You have IE6 which is the bane of any web developers existence. Luckily it has just about run its course and we don’t bother with the details for this browser any longer.
Most people now have IE8. However, IE8 has a compatibility mode which is supposed to make older sites look better. It sucks. IE9 has compatibility mode which look like it mimics IE8.
These problems could be avoided it IE would just force browser upgrades down the chain and program to the standards like Chrome and Firefox.
My main reason for choosing Chrome over Firefox is speed. You click the Chrome link and it opens now. You hit Firefox and you have to wait for a bit. you hit IE and you should be shot.