I guess you are using Firefox which doesn't play well with the forum software unless it is V5 or earlier. I recently got so fed up with it for that and other reasons I switched back to IE...... but I still find that too restricting for add ons and other limitations.
I'm now back on FF V18 with IE tab which works well. Chrome also works but I just don't like it much.
Switch browsers or install IE Tab is the answer.