I've been having a lot of problems with firefox suddenly refusing to work. When browsing firefox will suddenly cease working as normal. Pressing Page Up/Down will only scroll through the tabs, not move the page up/down. If I try to type anything (either in a search bar or on a webpage etc) it will instead act as if I've done a shortcut (opening the upload file menu for instance). The only way I can get firefox working as normal is to close everything down, meaning I lose everything (lost tabs won't reopen either when this happens). This isn't the result of me accidentally pressing a key; it will spontaneously happen even when nothing has happened. I will be scrolling down a page and suddenly my tabs will start moving instead. It's really infuriating and like playing Russian roulette. I've lost a lot of work because of this and it's getting to the point where I'm better off using another browser as I'm sick of taking the risk. How can I stop this from happened?