I did not find any duplicate for this. To reproduce: launch mozilla and open the sidebar. Expected results: Panels should be displayed as they've always been, ex. bookmarks are arranged in one single column. Actual results: Every panel's content is duplicated, and appears in 2 adjacent columns. Columns may overlap depending on sidebar's width. Ex. in the bookmarks panel, you get 2 columns. Each contains your bookmarks, and works independently from the other. Platform: Linux. 2000-04-05-08 worked fine, and 2000-04-06-16 did not. 2000-04-07-08 still exhibits the problem.
dup, has been fixed *** This bug has been marked as a duplicate of 34955 ***