Hmmm, okay, using the modified quiz.php file that you uploaded around the middle of this thread, I got a quiz to work, but some of the questions were missing from the question pages.
Using the above modification to the original quiz.php file, now it asks the first question - but the question text doesn't appear. On selecting an answer, it loads the same question again, and on selecting an answer it generates the "Sorry, you may not re-submit an answer." error.
Check it out here:
http://x-mencomics.com/xfan/forums/q...zid=3&taking=1