Load https://developer.mozilla.org/@api/deki/files/2921/=rotated-google-sample.html and scroll it a bit. The scrollbar of the iframe isn't painted properly.
I don't understand. I don't see any scrollbar(s) other than those in the page where I load this URL. Either in FF or Safari. Please be more precise :-) Also, please indicate whether this is OS-X-only or cross-platform.
Created attachment 354244 [details] screenshot Doesn't seem to happen on Linux, but on OSX if the page (in this case Google News) is long enough to cause scrollbars, they are painted to random places. So to test click 'News' in the iframe.