This problem has plagued me since Firefox 4 came along. On my FitPC I run Windows XP Pro, use a logitech wireless mouse and keyboard, have 2 gigs of ram and enough processing power, but when I install any version of Firefox other than 3.6.xx, the mouse movement jerks when passing over links and buttons, rendering it almost useless. On and off I have researched this problem on the web, as I am obviously not alone in having this fault.
Anyway, the reason for this post is to document so that it may be easier for others to find a solution. I was reading one of those waffly forum type sites where people who can’t spell give other strange people useless advise on things they obviously know nothing about, when one sharper person replied with “I switched off hardware acceleration and it worked for me”. That was one I hadn’t tried, and when I did it worked! Why did it taker me many months to find this, why isn’t it prominent somewhere on the Mozilla web sites somewhere – or is it and I am just looking in the wrong places?
Anyway, go to Tools/Options in the toolbar, and untick “Use hardware acceleration where available”, and restart firefox. No more jerky mouse, and I can let firefox update itself happily rather than continually refusing it, and all my machines can have the same version. No more (or somewhat less) nagging.
Firefox is getting a bit like adobe, in that you spend more time downloading and installing updates than actually using the product, especially if you have a network of several machines to maintain.