I've installed the CiviVolunteer extension on CiviCRM 4.6.6 on Drupal 7. I can create an event, enable volunteer management, assign volunteers, etc., from both the site's administrator account and from accounts part of the more permission-limited "staff" roll. As the site administrator I can also use the "Log Volunteer Hours" form without issue. However, when I try to use this form as a "staff" user, the form comes up and is populated, but the spinning "loading" triangle never goes away, and my cursor turns into an hourglass over the form. According to the browser console, when I run the page (and the form) as a "staff" user, there is an uncaught TypeError related to the jQuery "each" function (specifically, it is being supplied with an undefined object); this doesn't happen when run as the site administrator.
What permissions does a user have to have to be able to use the Log Volunteer Hours form?