Firefox isn't saving the tabs that I pin as app tabs for the next session
Firefox just updated itself on my laptop. Ever since this update, whenever I pin a tab as an app tab it pins but doesn't save it, so when I restart Firefox the app tab isn't there. I looked at the Help section, and my privacy settings shouldn't be a problem. It's set to use custom settings for remembering the history, it is specifically set to remember the browsing history, and it is not set to clear the history when I close Firefox.
Additional System Details
- Google Update
- Shockwave Flash 10.3 r183
- McAfee MSC FF plugin DLL
- RealJukebox Netscape Plugin
- RealNetworks(tm) RealPlayer Chrome Background Extension Plug-In
- RealPlayer(tm) HTML5VideoShim Plug-In
- RealPlayer(tm) LiveConnect-Enabled Plug-In
- Adobe PDF Plug-In For Firefox and Netscape 8.3.0
- DivX VOD Helper Plug-in
- NPRuntime Script Plug-in Library for Java(TM) Deploy
- Next Generation Java Plug-in 1.6.0_26 for Mozilla browsers
- iTunes Detector Plug-in
- DivX Web Player version 18.104.22.168
- Adobe Shockwave for Director Netscape plug-in, version 22.214.171.1240
- The QuickTime Plugin allows you to view a wide variety of multimedia content in Web pages. For more information, visit the QuickTime Web site.
- McAfee Virtual Technician plugin for Mozilla (Gecko Version: 1.8b1)
- Windows Presentation Foundation (WPF) plug-in for Mozilla browsers
- User Agent: Mozilla/5.0 (Windows NT 6.0; rv:7.0) Gecko/20100101 Firefox/7.0
App (pinned) tabs and Tab Groups (Panorama) are stored as part of the session data  in the file sessionstore.js  in the Firefox profile folder .
Make sure that you do not use "Clear Recent History" to clear the "Browsing History" when Firefox is closed because that prevails and prevents Firefox from opening tabs from the previous session.
-  http://kb.mozillazine.org/Session_Restore
-  http://kb.mozillazine.org/sessionstore.js
-  http://kb.mozillazine.org/Profile_folder_-_Firefox Firefox
It is also possible to use the "Show my windows and tabs from last time" setting, that is usually a more reliable way to restore session data.
- Firefox/Tools > Options > General > Startup: "When Firefox Starts": "Show my windows and tabs from last time"