I have just had a new hard drive after a crash and a problem I had when the machine was new has come back. Unfortunatly I can't remember how I fixed it originally. The problem is that when I use the mouse to move the cursor if I leave it briefly it acts without me clicking. This can be to scroll or to run a program or open an email whatever. I have looked for a setting in all the obvious places (keybard, mouse display etc.) but found nothing. Also, the letter "o" does not always type. Both seriously inconvenient. The machine is a Toshiba Satellite running XP. Help please!