Thanks, I'll try that too.

I did find a some alternate utilities (DoubleTake, Stitcher and Hugin). DoubleTake is really easy to use but results aren't as nice. Hugin seems complicated so didn't try. Stitcher is high-end commercial and complicated.

I also found a newer version of Canon's PhotoStitch which runs under OS X but the results from the OS 9 version are better.

The image above is fairly close up for this kind of shot, hence the excessive distortion and glitches at the seems. Images with distanced horizons fare much better but objects in the near field tend to distort.