Template error with django-photologue: 'Permission Denied'

Question

I'm in the process of re-setting up my Django development environment after reinstalling my OS. We use django-photologue with our project, which I installed using easy_install. However, I'm getting a template error on every template that has a photologue photo:

TemplateSyntaxError at /newsroom/news/ Caught an exception while rendering: (13, 'Permission denied')

One example of the line where the error is located:

<img src="{{ photo.get_list_url }}">

I'm totally stumped--I've used photologue for this project on many different platforms and have never had this problem. Google yields nothing. I'm currently using Jolicloud (based on Ubuntu Jaunty). I'm working with a pre-existing database, so all of the photo sizes and everything have already been set up.