Since March 8, toolbar buttons can get focus in modern theme. (1) Load some URL in a browser window. (2) Click back button on toolbar to load previous URL. (3) Press space key. Navigator backs insted of page down. This is focusing problem. Back button gets focus after it was clicked on, so following key input go to back button. On March 8, some focus properties in mozilla/themes/modern/communicator/button.css, were altered like this: - -moz-user-focus: ignore !important; + -moz-user-focus: ignore; I'm not sure how "!important" works, but reverting these solves problem.
Adding modern keyword.
CC'ing hwaara. Like you did for the broken menubuttons, could you come up with the patch real quick and check it in? ;) Thanks.
*** This bug has been marked as a duplicate of 71460 ***