Zenphoto with ImageMagick still won't create thumbnails for the same exact images that GD would choke on. I've always assumed it was PHP memory issue, but now I'm wondering if something else going on.
For example,
This image is 2592x3888 and 3.9 MB. Thumbnails get created no problem.
http://photos.fox-clan.com/albums/2009-T-Ball/2009-03-26%2006-11-33.jpg
This image is same exact resolution and only 2.7 MB. Thumbnails don't get created.
http://photos.fox-clan.com/albums/2009-T-Ball/2009-03-26%2006-33-32.jpg
It seems to have something to do with the orientation of the photograph and perhaps even something to do with the orientation flag set in the EXIF. Images with Orientation flag of "Right Upper" seem to be the ones that fail on thumbnail creation. It the Orientation flag says "Upper Left", it works.
Not sure if this is related to Zenphoto or graphics processor. Either way, hoping I can just change the EXIF flag and get thumbnails...