I'm using my laptop when I type documents and I tend to encounter this at times as well. This happens when my hand touches the touch pad. What I did was disable its touch pad so I wouldn't have to deal with it again.
I prefer playing Guild Wars. Probably because I've been playing it longer compared to WOW. WOW seems great but I'm kind of a beginner on this game so I'm not all that good at it yet.
