[ptx] hugin/nona zenith bug?

[scholnik at radar.nrl.navy.mil]

I have a 2 row + zenith pano that I loaded into hugin and stitched
with both nona and PTStitcher.  PTStitcher seems to work fine, but
both nona and the hugin preview seem to lose the zenith image.  nona
claims to be remapping the zenith image, but it doesn't seem to make
it to the final image.  In the preview window it seems to be clipping
everything above some pitch.  Is this a feature or a bug?

Dan Scholnik