PS4 photomerge inconsistent . . . ??

LiveAwake

So I'm playing with a panorama I took during a recent trip to Nevada. It consists of 10 vertical images, which I then stitched together using CS4's photomerge function. I had hoped to make 2 iterations of it, with an exposure adjustment in ACR, that I could then blend together for a sort of rudimentary HDR that would give me good exposure in the sky and in the foreground.

To my chagrin, when I ran the photomerge the second time, the result came out differently shaped than the first one!! Here are some pictures:

First:


Second:


Is this normal? Is there any way to force photoshop to use the same overlay pattern so that I can get two images that have the same shape??

colourbox

Which photomerge option did you pick for each one?

LiveAwake

I did the exact same thing each time. I just left it on auto.