User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9a8pre) Gecko/2007082920 Minefield/3.0a8pre Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9a8pre) Gecko/2007082920 Minefield/3.0a8pre After opening several menupopups from the bookmarks toolbar or from the bookmarks menu going to full screen and returning from it is noticeably slower. Depending on the number of popups it can take 2 seconds or more till full screen is fully called. Tested with a Thinkpad T60 (ATI X1400, Windows XP and Ubuntu 6.10) and a Desktop (Athlon 2600+, ATI 9200, Windows 2000) with a "clean" profile. The profile was created with Fx2 and the (following) attachment was copied into the profile. After that Minefield was started with that profile. Reproducible: Always Steps to Reproduce: 1.Use the bookmarks from attachment or make sure that your bookmarks contain several folders 2.make the folders popup (via mouse or keyboard) 3.go to full screen (F11) Actual Results: Minefield slows down Expected Results: Like in Fx 2: no slow down Attachment will follow

This one is strange. The only thing I can say that entering/leaving full screen mode in Gecko 1.9 is VERY slow, when bookmark-menupopups where opened. The more menupopups were opened the slower. Because it's also a case in Seamonkey 2.0a1pre I don't think that it's releated to places. Setting and resetting the "hidden" attribute on the navigator-toolbox or the bookmarks-menu and bookmarks-toolbar will reset to normal speed. For me it seems that setting attributes while entering/leaving fullscreen is incredible slow after several bookmark-menupopups were opened.

Also in : Mozilla/5.0 (Windows; U; Windows NT 5.1; de; rv:1.9b3pre) Gecko/2008010405 Minefield/3.0b3pre ID:2008010405 FX slows down after using bookmarks-manager.

The same in: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9b3pre; .NET CLR 2.0.50727) Gecko/2008010805 Minefield/3.0b3pre

UNCONFIRMED > NEW. Same user agent as christian.

Bug still present in trunk and Namoroka. Better testcase will follow.

After injstalling the extension you will find a button labeled "Test Menu" in the nav-bar. After hitting the button, mouse over the submenus. Toggling full screen or deactivating/activating the window is slow. "Toggle hidden" in the Test Menu restores normal speed.

This issue is not reproducible for me on Windows 10 and Windows xp with the latest released of Firefox version. I am not able to install the extension mentioned in comment 7. Considering the age of bug and the fact that it's not reproducible for me, I am closing this bug as resolved:work for me. Feel free to reopen this bug if you still encounter this issue.