Hi Steve
I have gone through the software repair tool that NoNine or in their response, not sure if it's solved the problem, but might be worth doing anyway.
I have discovered that the problem of ghosting only starts occuring when the device is working hard, i.e. has a couple of heavy programs running at the same time. This suggests it's a hardware issue, but i only ran one big program at any one time yesterday, and it worked fine all day. I know it doesnt solve your problem, but it might help you get through africa without having to do without your surface for a while.
Ultimately though, this needs a replacement device, none of the software repair tools work, but they might just iron out some unknown creases in other programs we didn't know were there.
Enjoy the ride, i am heading there next April on my KTM.