My browser is fully updated for my Macbook Pro. For the first time ever, I have encountered a problem with Firefox. When I select Bookmarks and click "Show all bookmarks" the folder opens up, swallowing the entire screen space and I cannot minimize, maximize or even close the folder. There are no icons in the top left hand corner as has always been the case. It also causes the top and bottom toolbars to disappear from the screen. The only thing I can do is click and drag the folder across the screen enough that I can move my cursor onto the Firefox alias at the bottom of my screen, right-click and select 'quit.' Then I have to re-start Firefox, open all my tabs and start from scratch. This is annoying the hell out of me. Why has it suddenly started occurring and what can I do to rectify the issue? Thank you