App tabs and Tab Groups (Panorama) are stored as part of the session data in the file sessionstore.js in the Firefox Profile Folder

• http://kb.mozillazine.org/Session_Restore

Make sure that you do not use Delete browsing, search and download history on Firefox to clear the "Browsing History" if Firefox is closed because that prevails and prevents Firefox from opening tabs from the previous session.

If you use CCleaner then make sure that Session is unchecked in the settings for the Firefox application.

• App Tab Initializer: https://addons.mozilla.org/firefox/addon/app-tab-initializer/

Thanks so much!!!!!!!!

You're welcome

I'm sure I still lose my App Tabs even when I don't use CCleaner (I checked and 'session' wasn't ticked) or Clear Recent History - mine never seem to last more than 3 times - IE, if I reset my App Tabs in the morning, then do what I have to do online and shut my PC down, then go back on in the afternoon, do what I have to online, shut down, come back later, shut down, then come back again, the fourth time my App Tabs will have gone. Is there anyway of 'locking' them, so I don't lose them, or is there something else I'm doing wrong?

Thanks very much.

I don't know about CCleaner, but I did uncheck "clear history" once I found it, and the lone app tab was present when I reopened FF4. Shouldn't you add that little item to your explanation of app tabs? Why is it necessary, btw? Perhaps you can make App Tabs separate from "history."

Thanks for the info...............