From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:0.9.7) Gecko/20020112 BuildID: 20020112 When I close the sidebar by clicking on the right side of it (the thing with the two >) and after that press F9 (which normally lets the sidebar appear/disappear), the closed sidebar disappears like it sould. when i press F9 again, it comes back, but this time open and empty. Sometimes its not empty, but incomplete, some items are missing. I have to close and open it again with clicking on the symbol with the two >. Reproducible: Sometimes Steps to Reproduce: close the sidebar with mouse-click and press F9 two times Actual Results: empty or incomplete sidebar Expected Results: the correct sidebar. I have testet under Windows and Linux and it appears on both.

Reporter, is it possible you are seeing symptoms of bug 119975 ?

Duplicate of "Sidebar contents disappears on hide and show" *** This bug has been marked as a duplicate of 116094 ***

verified.