I love the hack! I would really like to see an addition to it -- an extra field called "Explanation". In this field you could explain the correct answer and show it at the end of the quiz. I can probably code this myself, but since you are more familiar with your hack you may be able to do it in no time.
Let me know..... and thanks again!!
[EDIT] I managed to edit the code for the extra field. [/EDIT]