as the mouse can also cause such problems.
Try a different mouse if you have one or just remove the one you have and see if things get better. If they do you know it is your mouse.
Look here first and maybe print it out if you aren't familiar with using Windows without a mouse.
List of the keyboard shortcuts that are available in Windows XP
Both page up and page down are randomly pressed. It has to be an internal problem as I already removed the keyboard and it is still there. I also tried restarted the computer but yielded no results. I was only to be able to type this peacefully by placing the mouse on a tab.
If any other information is required then let me know.