Re: Why can't I click back, 1 page, with my mouse or backspace and left arrow on screen?
I'm sorry you're having this problem. Currently, Firefox does not offer functionality to customize these keyboard shortcuts. As such, if they're not working on your computer, I would check to see if you have any other programs which have keybinds that may interfere or override other programs. (For instance, I run Linux, and have key combinations which make interesting screen effects. If I were to keybind Alt-Backarrow to one of these effects, it could cause a problem.
Here is a list of the programmed combinations. Click here If you cannot get Alt-Backarrow to work, try Ctrl-[ .