when composing a message, you type in the first letter of a name and you see the names show up in a dark red box.
in FF you can click on it an nothing happens. you have to type it all in.
in IE6 - even worse - once the box shows up you cannot get it to go away - ever. so you better do the subject and the message body first. then pick who to send it to.
now i cannot believe that everyone has this problem. but that is what it does for me using WinXP with FF and IE6.
i had been testing with FF and it was just a pain, then when i just tried IE6 for the first time . . .