Normally, at the top of the screen there are the tabs, which show which site I am using and which sites I have open. Currently, those tabs disappear and the screen is filled completely with the page that I am working on. Only when I jam the curser up to the top of the screen, do the tabs appear. They disappear again when I move the curser down from the top of the screen.

This began when I was trying to pay a bill online (American Express). The site would not function and allow me to pay the bill. The AX "help" person told me that Firefox was the problem and made me change to another browser, but while I was still on Firefox, the tabs disappeared. I was ultimately able to pay the bill on another browser. BTW, I had not been able to pay the bill for about a week, but on my previous tries, the tabs did not disappear. The "help" person said that my cookies needed to be deleted or some such. I have been paying bills on line for years, why would cookies and my browsing history interfere with paying a bill, all of a sudden? I love Firefox and I did not want to use another browser (IE is even deleted from my computer).