Comment 89 for bug 230102

I also had this problem after I switched from Firefox 2 to 3 recently. I searched for this using Internet search engines and found some related topics about this problem, some of which had some workarounds proposed. I also found this page through a search.

Just a note for those who has the same problem and find this page through searching. There is a workaround to this problem and I have tested it and it really works.

After you launch the browser, don't forget to open another browser window besides the main window you actually use. You can leave the second window open and drag it out of the visible range of your desktop so that you cannot see it.

When you click the "x" button of the main window, due to the fact that there are more than 1 window open on the machine, you will get the warning asking whether you really want to close it. Now, don't forget to select "cancel" otherwise your main window will get closed and cannot be restored. Instead, you can manually close second window (which should be blank) first and then click the "x" button again to close the main window this time. The whole procedure serves as a warning so you will not get the main window closed accidentally any more.

There are also some side effects for this workaround. The first one is that the procedure is a bit little complex, which you will have to get used to. The second one is that if you accidentally select "Close tabs" for the closing warning while the second window is still open, you wont be able to have it restored, which should also be taken care of.

Generally speaking, the mentioned workaround works well for me and I hope this can help those who also meet the same problem as me.