For the past few days I have been unable to close tabs. Clicking the "X" in the right corner of the tab does nothing. I can open new tabs though. It's really annoying. And yes I've restarted it and all that crap.
I tried all of this and it didn't work. Someone else posted a solution that worked for me. check your Home page dialog box- I had multiple URLs listed in there, so each time I started Firefox, it would load all of them. It also explained why each time I clicked the Home button, it would reload all of the tabs again. I just cleared the field in the dialog box, put in one address and voila!