P: Pano merge of IQ3 100 files incorrect orientation

When doing a pano merge of several files taken with a Phase One IQ3 100 back, the merge is always in the wrong orientation.  I have tried merging several horizontal panos, and LR always creates a vertical pano.  After merging I can use the rotate tool to obtain correct results, so the issue isn't serious, but it is a challenge to evaluate the pano when it's vertical, since it is much smaller due to the limit of the screen height.