Windows 7: "Show Desktop" self-activates randomly

3 month old laptop, mostly pretty happy with, except for slightly erratic touch-pad, but several times a day, the mouse pointer, all by itself, runs to the lower right of the screen, and clicks the "Show Desktop" icon (even with no hands on the touch-pad/keyboard at all). . . The first few times I panicked, thought I had lost a ton of work/play, as all my normal dozen open apps just vanished. Now that I know what it is, it is not so bad, I just "click" and everything comes back. But seems to be getting a little more frequent, and it could become a real $%^&*(.

So, any ideas at all welcome. Hardware? Software?, Drivers?, Alien infestation? Poltergeist? Virus?

Poltergeist was my first guess, malware would be my second. Have you tried running any anti-malware program? MBAM is a good choice and free.

I hope I am not being premature, but the problem has not shown up for several days.

This laptop has no hardware audio volume control. The Touchpad has a "Tap Zone" feature where a finger tap on a corner will perform one of several actions. I had set it to act as a volume control to substitute for the missing hardware control. While debugging, I changed a few settings, and it is possible that it is something else, but I think disabling the "Tap Zone" feature has fixed the Poltergeist. I will report back if this turns out wrong, but for now, I think I will call it solved, and just learn to do without a quick volume control.