Cant merge properly

I scanned in the same transparency 3 times at different densities to merge together. I did this on a flat bed scanner. The 3 scans were EXACTLY in the same position, you would have to go out of your way to misalign them. Well this app did it! Every time. And also it only lets you merge 2 images together. I will be requesting my money back.

96!! about True HDR, v3.3