I upgraded to Firefox 4 this morning and noticed for all pages in Stack Overflow I am getting the following pop up. I read this question, but that did not work. I did not get this with Firefox 3.6 though. Any clue on what might be happening?
(The image button in Firefox 4 is also broken when I click on it pastes my clipboard content.)
For security reasons, framing is not allowed; click OK to remove the frames.
Is this something to do with Firefox 4 rendering?