It believe the render was finished, I did not pause it, and as far as I know you can only save the render it when it's finished.
I've just loaded the tgd and you can see it on the 3D preview it you let it complete and on a quick render.
If you move the cursor over the black in the 3D preview you get no x, y and z co-ordinates. Even if the cursor is over the sky you usually get a y co-ordinate.
Actually, If you move the camera straight up, theres is a lot of black, and before you lose the x co-ordinate it jumps up to the 28,000 mark the starts to decrease again but rapidly before disappearing again at around the -10,000 mark.
Weird.
Dave