Created attachment 793433 [details] Example of the bug, captured from io9.com User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:24.0) Gecko/20100101 Firefox/24.0 (Beta/Release) Build ID: 20130819170952 Steps to reproduce: Firefox 23 and 24beta on 13" MBP Retina. An embedded Youtube clip on a page shows only the upper left quarter of the video. The remaining 3/4 of the video is black. Actual results: I dumped all add-ons and extensions. No change.
dupe bug 903296?