I cleared the cache, deleted the cookies and even tried to open it up with disabled firewall. The only thing seeming to solve my problem is deactivating JavaScript and preventing facebook from loading the chat (the freeze occurs after nearly the entire site is loaded, except the chat). I updated my graphics drivers. Facebook on IE and Opera works fine. The freeze occured for the first time after an automatic Java update today. There is no Bug report stored cause firefox just freezes and does not respond anymore (I have to force a close via task manager).