Trying out the demo and i've run into the same problem.
Though in my case the resolution and camera are definitely superior.
Using a canon 20d at 8.2 mpix (3500x2330 px) and getting very inconsistent results between the same alignment sessions. Sometimes it works perfectly, other times it fails completely.
The focal lenght and pixel size are also automatically detected correctly.
Sometimes i run the alignment with pair preselection set to disabled, and it keeps failing, then i suddenly change that to generic and i get a perfect result. Then i run it again with it set to disabled, and now it works, even though, before it was failing.
Sometimes i close the application, and when i start it again, it gets a perfect result from the first try.
Other times, i try it 10 times in a row and it keeps failing, with the exact same settings and images.
Wish i could understand a little better what happens under the hood, and why at times i get a perfect result all of a sudden. Specular reflections might be a cause of failure of course, with light moving across the surface of the barell, but in that case, shouldn't it fail every time?
Here's some pics to better depict the problem. As you can see in the couple of example images i've attached (40 in total), they are pretty well lit and i've also used some square markers hoping that it would help with the alignment.
Any suggestions would be highly appreciated,
Thanks,
Octav