User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:2.0b6) Gecko/20100101 Firefox/4.0b6 Build Identifier: Mozilla/5.0 (Windows NT 5.1; rv:2.0b6) Gecko/20100101 Firefox/4.0b6 App Tabs that you've turned back into normal tabs return to being App Tabs when you restart Firefox. Investigation required to find out what triggers this, as it does not always happen. It always happens with certain of my tabs in certain groups (cannot provide links, they're on our network). Reproducible: Sometimes Steps to Reproduce: 1.Open Firefox 2.Tabs restored from previous session, these include 4 tabs in group a and two app tabs in group b 3.Turn the app tabs in group b into normal tabs 4.Close Firefox 5.Open Firefox Actual Results: The 2 tabs in group b are app tabs Expected Results: They should be normal tabs

Just tried replicating this again and the result was different (but still wrong). I closed all my tabs and tab groups so I was starting from scratch. I created four tabs in one group, created two tabs in another group. Restarted Firefox. I turned the two in the second group into app tabs and restarted Firefox. They stayed as App Tabs. I turned them into normal tabs and restarted Firefox. Now they were normal tabs, but they showed up in the wrong tab group until I clicked Group Your Tabs, which corrected the problem. This would be a different, probably easier to fix error. I'll update if I can recreate my original problem.