when i am upload image on photo album on demo.jcow.net.
It not upload jpg format and show Sorry, the pic type is uncorrect, than which format support. Show message when uploading is 80% done. When you upload image,that time show this message in same page not web like error. same image i upload on facebook it uploaded.

This bug has been fixed in Jcow 3.1.0.
Thanks for reporting.