I recently installed Piwigo 2.0.1, and everything looks like it will do what I need it to do.  However, I cannot get the program to create thumbnails of nearly all my pics (loaded in the "galleries" directory).  The program will recognize that they are there, but when I go to have it make thumbnails I am redirected to a blank screen.

I would think that maybe my server is the issue, but three thumbnails (out of about 140) were generated.  All files are .jpg.  The only difference with these three photos that worked (that I can tell) is their original size (not sure exactly without looking, but somewhat smaller than the other photos which came right off my Canon camera).

Any ideas as to how to fix this?  I would really like to use Piwigo, but it won't work if I can't resolve this (because I sure don't want to take the time to make thumbnails of all the pics myself).