Problems with .pdf and mobile

Hi,
Wonderful plugin!!!
We are running a site with lots of photos with some .pdf’s attached to them …. as for example here:
http://flinflonheritageproject.com/sports/?wppa-cover=0&wppa-album=90&wppa-occur=1&wppa-page=3
On this page, choose picture #1002111 and try to download the pdf with a mobile device. Doesn’t work.
Now go to
http://flinflonheritageproject.com/text and try to download the same pdf with a mobile device. Works fine.
Both links work fine with a regular computer.
Any ideas? This seems to be the case for every .pdf attached to a wppa photo.
Ken Penner

http://wordpress.org/plugins/wp-photo-album-plus/