Your Answer...Are you using the the touch-pad?
Worst invention ever, not to mention sl-o-o-o-o-w.
You can't do anything useful with that. Get a wireless mouse.
I agree with AZardoz about the touch-pad, but that's just a personal preference. If you are using a mouse, does the battery need changing?
If you're already using a wireless mouse I find that re-seating the wireless dongle in the USB port can help.