Some of my pdf files generate thumbnails without an issue, and some don't. Here's a link to my site.
http://www.bville.lib.ny.us/omeka
The PDF files were batch encoded by an outside contractor before I joined the library. The 2006 and later issues of the paper generate thumbnails just fine, and the 1999 and earlier issues generate thumbnails without a problem, but the issues from 2000 to 2005 all fail to generate any thumbnails.
Any idea on why I'm getting this failure?