Course Units page times out when not logged in

We have run into a unique issue where a user who is not logged in and finds the Course Units page is getting stuck in a loop until the page times out. We have the timeout set for 4 minutes.

We have turned off all plugins and activated the default theme with no luck. We have found that if you link to a specific page inside the unit when you are NOT logged in you are redirected like you should be to the course description page. For some reason when you go to just the Units page it can't redirect.

Here is a line from our error log that should help:

mod_fcgid: stderr: PHP Notice: Undefined offset: 93 in /wp-content/plugins/coursepress/includes/classes/class.student.completion.php on line 453

Here is the link to the units page that will time out:
http://learn.speedsecrets.com/courses/performance-driving-101/units/

I have already granted access on http://learn.speedsecrets.com.