Problems with Browsers

I'm having a problem with my computer that seems to be getting worse. I first noticed it while using Mozilla Firefox browser (which I use to view AF.) Now the problem has drifted over to IE browser which I use for other sites, and my email accounts. The problem occurs when I attempt to click on a thread on this site, or a specific email I wish to view, and as I'm clicking on it, the whole page suddenly moves up. I usually end up clicking on something else I do not wish to look at as a result.If I move the page back down and retry to click on the link I want , it does it again. It seems like the browser is playing a game with me to see if I can click the link I want before the browser moves it on me. The problem seems worse in certain areas of my screen, like the middle third of the screen. If I move the page to where the desired link is located to above or below that point , then the problem doesn't seem to exist. Does anybody have an idea of what the problem could be, or themselves experienced this sort of problem? Or does anybody have a solution? I'm not sure if it could be called "browser hijacking". I have read a little bit about that subject. I have all sorts of adware/spyware/antivirus programs running and regularly updated, and when I run the scans, nothing major comes up, ( actually very little comes up when the scans are done.)Could there be something else I need to look at. Any help would be appreciated. Thanks.

Might be your mouse. Windows XP and mice sometimes have odd issues. Even mine does wierd things every now and again and I've known other people where it did odd things, such as scrolling on its own and things like that. Try either switching your mouse and see if that helps or if it's a USB mouse, put a PS/2 adapter on it and see if that does anything (thereby taking it off the USB driver and using the PS/2 hardware port).

For the record, I have a Microsoft optical mouse and my other acquaintences had optical mice as well.