Created attachment 618243 [details] Downloads_screenshot.png STR: 1. Customize your Navigation toolbar and remove the new Downloads button. 2. CMD+J to open the Downloads doorhanger opens. AR: The Downloads doorhanger draws some rendering artifacts on the Navigation toolbar. Please see the attached screenshot. ER: No rendering artifacts!
This problem seems to have gone away when I retested with Nightly 15.0a1 (2012-05-09).