Long time bug and annoyance for me. Firefox is my default browser for 10+ years. When concentrating on reading a page, and slowly scrolling at the same time, the mouse cursor can drift off the scrollbar even though I have the mouse button held down. It is because I am focused on the page, the mouse can lose perfect vertical sliding action, so the cursor drifts into the page. Soon it can no longer hang on to the scrollbar and the page jumps back to the top. Is there any fix that can stop this from happening ? The mouse cursor should stay on the scrollbar as long as I have the mouse button held down.