I replaced Vista with Windows 7 using a clean install. My wife's laptop came with Windows 7 preinstalled. On both of our machines, the cursor occasionally jumps to a different location while typing. (Example: in an email reply, it will jump from the reply I'm typing down to the previous message.) We've noticed it in Word and Firefox email because we use these the most, but it may happen elsewhere.
Does anyone know why this happens, and more important, how to fix it? I use Microsoft Security Essential as AV and regularly do scans with Malwarebytes, Spybot S&D, Ad-aware. Would a Hijack This log show anything?