Make sure that you do not use Delete browsing, search and download history on Firefox to clear the browsing history.

App Tabs are stored in sessionstore.js as part of the session data, so make sure that session restore is enabled and is working properly.

See also:

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

Thanks that fixed it.

I do not have or use clear recent history. I do have Show my windows and tabs from last time. What happened is that I had two FF windows open, 1st with app tabs, 2nd (opened later) without. I closed the first window, then closed the 2nd window, now FF always starts with that 2nd window and no app tabs. This is a pretty stupid bug IMHO that should have been caught.

Indeed JNavas. If you make app tabs, I think it should show on all windows you have opened (as those are important and small in size).

I made the Gmail and Hotmail app (and have option that it shows the last tabs and windows). But if you then open another window with tabs and you close the one with the apps, it will be gone for all of them. There should be an option to save them and to show them on all windows.

Cor-el - Thanks for posting the fix. However, wouldn't it be more logical to store the app tab(s) along with bookmarks, perhaps flagged as app tabs, rather than in the sessionstore.js file? That way, you could still maintain privacy in your browsing history.

Not only did I lose the App Tabs but my toolbar customizations as well. I took a suggestion from another thread and deleted the sessionstore.js and sessionstore.bak but soon the same thing happened. My settings are right and I did NOT have a second window open - although I did preciously. But at the time I closed the application, only the one window was open WITH the app tabs and customizations. This is a flat out bug and a very inconvenient and irritating one. Hope it is fixed soon. Firefox 4, Win XP Pro SP3

App Tabs SHOULD NOT be stored in session history! The purpose of an App Tap is to point to a particular URL. The history of sites selected before that URL is meaningless. Clearing, or not storing, my browsing history should not affect the App Tabs I've selected. This is an implementation error that needs to be corrected.

Try this extension:

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

Keeping AppTab data in sessionstore.js is one of the worst security decisions the FF team could have made. I routinely delete recent history upon exit. I wouldn't use FF if I couldn't. AppTab data belongs elsewhere and should be moved forewith. In the meantime I consider AppTab broken. Team FF should stop crowing about the feature until it works.

Only the gullible trust add-ons in a matter as basic as security. Such things are best left to the development team. See my post on AppTab. The feature is broken, pure and simple. Don't use it if you are at all concerned with security.

It seems this problem is still happening even up to Firefox 12. It just happened to me, and I did some tests.

Even with private browsing off, the app tabs just keep disappearing. I did some tests all centering on the Options->Privacy->History section.

I had changed it to CUSTOM, and I select each option to test which was the one causing the "problem", even for people who did not have private browsing on and such.

I have found that the problem lies in the COOKIES.

You NEED to select "Accept cookies from sites, then "Accept 3rd Party Cookies", and under that, you MUST select "Keep cookies UNTIL THEY EXPIRE".

Any other options will cause the app tabs to disappear.