As you can see in the screenshot, the edit question seems totally broken on StackOverflow (not on Meta). This also happens when I click Ask Question.
Notice the empty preview, the missing buttons, the non-working shortcuts (i.e., Ctrl-L for a link and Ctrl-I for italics don't work anymore). I'm using FF 3.6.6
This is not a double of this one, because of its age and the current situation is just new.