If you try going into Recently closed Windows, or Restoring your Previous Session, does that help?

I use an add-on called Tab Mix Plus 0.4.0.1 under extensions.......you can tweak it the was you want....can save the last 2 times had firefox open or crash..... Can set it up so will ask you everytime you open FF if want to restore last session....

It has helped me out so many times...the little pop up window is well worth the click

Doh ! Stupid me - tried recntly closed windows and got them all back. Feel very silly, as been using FF for years !!

those things happen....good thing is your fixed

I think Firefox should always restore all closed Windows with all opened tabs by default, not just the last closed. In my opinion many user don't know about the "Recently closed Windows" menu. Neither do I until now and I have been using Firefox for many years too. :)

Edit: I found it now: http://kb.mozillazine.org/Session_Restore

"If you want Firefox to restore multiple windows you need to close Firefox via "File -> Exit" ("File -> Quit" on Linux, "Firefox -> Quit Firefox" on Mac OS). Closing the windows one at a time will cause Firefox to only restore the last window that was closed."

Closed tabs and closed windows are never restored.
If you close a tab or window then you don't expect to see it the next time.
That would be very inconvenient.

Tabs and windows that were open will be reopened the next time.
Firefox won't restore the previous session unless you select that.

• Tools > Options > General > Startup: "When Firefox Starts": "Show my windows and tabs from last time"

Sorry, I badly formulated my previous post. I meant Firefox should always restore all closed Windows with all opened tabs by default WHEN "Show my windows and tabs from last time" selected. I always use that option so I forgot write it down. Sorry :)

Firefox will restore all windows and all tabs when File > Exit or Exit from the Firefox button is used. Closing one window and then closing another window is where users have a problem, as Firefox only "restores" the last window that was closed all by itself.

garferi, thanks for the pointer about File -> Exit. However, I find it a clumsy solution: no one is using File -> Exit if there is a closing button. No one will ever know this crucial difference between the commands unless they do specific investigation. There is no keyboard short-cut for that File -> Exit command either, even as the Mozilla folk are advising to use it.

Consider this. I have opened a lot of tabs. I have created several tab groups, and I have opened a lot of tabs in each of them. I open Firefox, do stuff, close Firefox numerous times. Then once I get a pop-under window that I miss. It's easy - they are designed to be missed. I want to exit Firefox, so I click on the close button. I am now left with the pop-under window. I close that one too, and upon the next Firefox start all my tabs in all my tab groups are lost.