Viewing a list of submitted assignments causes a log entry to be created. When the log is viewed later, the Action column in the log shows assignment view submission. However, when one clicks on that link, you're shown submissions from an entirely different course.

This would seem to be a known problem, since http://moodle.cvs.sourceforge.net/moodle/moodle/mod/assignment/type/online/assignment.class.php includes the comment:

//TODO fix log actions - needs db upgrade