Re: Student ability
Dave, has the student progressed in comparison with where he started? Has he made improvement? Don't compare him with the other students; instead measure his own progress within himself. What rank are you testing him for (or not testing him)? There would be a vast difference IMNSO between gokyu and ikkyu test in terms of the absolutes you expect of your students.
Someone mentioned focus earlier in this thread, and perhaps preparing for a test can be a catalyst for focus. Maybe that is part of the problem, just like only being able to train twice a week. One more thought-do you have any kyu test videos from your organization that you can lend the student to study? Sometimes these can be quite helpful.