User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.1) Gecko/20061204 Firefox/2.0.0.1 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.1) Gecko/20061204 Firefox/2.0.0.1 If Download Manager is open when Firefox browser window is closed and Download Manager is not closed before the browser is opened the next time, previous session's tabs are lost and browser opens with only one empty tab. Reproducible: Always Steps to Reproduce: 1. Use browser setting When Firefox starts: Show my windows and tabs from last time 2. Browse and open tabs you'd like to keep open 3. Open Download Manager 4. Close browser 5. Start browser again Actual Results: Browser opens showing one window with one empty tab. All previously open windows are gone and forgotten. Expected Results: Browser opens showing my windows and tabs from last time.

That's because the browser did not really close. The process firefox.exe is still running in the task manager. The process will end when you also close the download manager. I think this bug is Invalid or a dupe.

I am also aware about the details of how this problem happens, it doesn't change it anywhere that it still is a problem causing severe data loss. When Download Manager is open without any browser window and the browser window is started, all the tabs that were previously open get erased from memory. This is a problem and needs to be issued. I think the best way would be to make Firefox aware when there is no browser window open, so that when only Download Manager is open and a browser window is opened, everything proceeds just like Firefox would have been just started. If your setting was "When Firefox starts: Show my windows and tabs from last time", the tabs from the previously closed browser window are now reopened. This way no data is lost. I can't think of a downside to this.

CC-ing zeniko@gmail.com if he is available.