The Pano Module is really strange it it's behavior. Or call it buggy since that's matching too.
I have 2 sets of pictures that can't be rendered als panorama because of some "unknown error" in the middle of the rendering process. Images itself look fine.
I have at least one set of 10 images that will only be rendered correctly when the last setting used in the module was the perspective one. If I set it to something other or change the setting and go back to perspective the panorama gets messed up quite heavily. (example at http://imgur.com/a/fF2Mo)
Sometimes, as in the upper example too, there is a big chunk of the panorama missing - every time on its left side. In the upper example half of the left plane.