I do a lot of autoscrolling, initiated by clicking and releasing the mouse wheel and controlled by moving the mouse away from me or toward me. A particular problem for me is that ending the autoscroll cleanly often fails. I try end to end the scroll by clicking the mouse wheel again. Sometimes this succeeds, but often it doesn't and I get scrolled very far beyond where I wanted to stop (after making repeated wheel clicks and/or left mouse button clicks). Sometimes, totally out of control. So, two questions: 1. What is Mozilla's intended way for the user to terminate an autoscroll event? 2. Can it be that the above problem is also related to keyboard lag (keystrokes often delayed by 1-2 seconds or don't ever make the screen) which I have been experiencing for some time? Maybe some mouse clicks are getting lost too, or are being delayed. I see in the forum and elsewhere online that a lot of FireFox users have had keyboard lag problems, in posts from many years back to the present, with few successful fixes. What is the best way for me to fix this? -- or is it a bug that needs attention?