I found that as I was typing on my laptop my cursor would jump around or the program of the icon under the mouse arrow would engage without my hitting the left touch-pad button.
After closer examination, I noticed during these cursor jumps while I typed the cursor was sent jumping to the location in my desktop window where the mouse arrow was located.
Apparently this is the result of a corrupted driver or a virus designed to annoy.
I'm running XP
Right Click on "My Computer" on your desktop
At the top of the window that appears left click on the "Hardware" tab.
Left click on the "Device Manager" button
Look down the tree of Device items and left click on the plus sign (+) to the left of "Mice and other pointing devices"
At this point you, under the "Mice and other pointing devices" heading, you should see one listed item (driver) if you're using just your touch-pad or one mouse.
Right click on that driver name, in my case it's "Snaptics PS/2...".
From the menu that appears when you right click on the mouse driver, choose "Update driver" by left clcking on it.
Follow the update instructions.
That's it. After you've updated your driver, reboot.