Hi Mike - what is happening here is your 2 images are on exactly the same plane so it is kind of up in the air which one will draw over top of the other.

To fix this, start the View/Image command, then go to the 3d view, and drag the front image to be a slight distance in Y in front of the back image.

You can drag images to move them around while you are inside the View/Image command.

Once they are separated by a little bit, their drawing order will not be ambiguous anymore and it should display how you want.

Let me know if you have problems setting this up.

- Michael