Since upgrading to Firefox 36.0.4 drop-down menus will not open sufficiently to display all the text inside. Also -- when I try to select text ... for instance, when I try to choose one of my bank accounts to transfer funds to another of my accounts nothing whatsoever happens. In other words, clicking with my mouse does nothing. I have similar problems in Firefox preferences. I can select a menu (general, tabs, search, content etc) and it opens, but not far enough to see inside. I had installed a plug-in (Theme Font and Size Changer) and wondered if this might be causing the problem, but I disabled it and there is no improvement.