This happened after I updated to Firefox 8.0.1. Same problem with 9.0.1. I'm on a Mac running OS X 10.5.8. I have not changed any add-ons, plugins, extensions, or anything like that. Every time a tab is dragged from my main window to form it's own new window, the tab button on the new window does not appear. I only have a + sign showing. A tab will show when I open a new tab, but the original "tab" does not appear. The + sign also appears on the left side of all new tabs. Isn't it supposed to be on the right? If I have 2 "tabs" open but only have 1 tab showing and try to close the window, Firefox asks me if I'm sure I want to close the 2 tabs. Tabs when opening blank new windows work properly. Dragging a tab to an already opened window works fine as well. Most of the time a tab is dragged out on accident, and it is quite annoying because I can't drag it back into the main window. Any help or suggestions would be greatly appreciated. Many Thanks!