See the editing help page. In Safari 5, at the very least (the only browser I have available at the moment), it has no background at the top, unlike most of the English.SE site.
Take a look at the editing page (just in case this is a Safari problem, I'll put up a picture).
I know that this has been asked before, but that was in May. The issue has either not been resolved at all, or was fixed, but somehow broke again. (Or was just never fixed for Safari, assuming of course that it was broken for Safari at the time of asking).