[Users] Frozen login screen - how to debug?

Hi, I am not able to use the ovirt GUI admin login portal. The screen is completely frozen (no response at all) after I enter the admin login name and password. The only indication is a warning message "Firefox 3.6 is not currently supported". I am not sure if this makes any sense. The same thing happens on Chrome and IE too. I have no such problem using CLI though. How can I debug this problem? - David