Upon opening Firefox, there is only one "+" tab. When additional tabs are open, they display the full webpage title and can be switched between by clicking on the tab/title. The original page is no where in sight. When I close all the "viewable" tabs, I end up with the original tab. I can only switch to the original tab when multiple tabs are open by clicking on the menu to the far right (also containing "tab groups"). I have not set any app tabs. Also, when I open a second window, the problem does not occur in that window, but if I close all windows, and re-open a new one, the problem is still there. (I am running Mac OS X 10.6.8, and just updated to Firefox 6, which is when I first ran into the issue)