Seems like you also have a double-posting problem!! J/K man.
Have you tried to see if there's an update for your graphics card? For example, mine used to do the same thing on the computer that I use to dupe dvd's. Every once in awhile while I'm on Google Earth zooming in or doing a fly-by, the computer screen would freeze just like how you described. This is just an onboard video card, but I did update the graphics driver (downloaded it off the internet) and now it's fine.
So yeah, if you have Windows XP, go ahead and let it report the problem and see what it says is the solution. That's how I solved my problem with the onboard video card.