Hi Peter,
Thanks for responding. I installed Moodle awhile ago (last year sometime) and just started a pilot class to test it out.
My hosting service, www.bluehost.com, offers it. So all I had to do was click an install button and it was installed like a desktop software. I did go up just now to the control panel for my site and there was a prompt to update. So right now I'm running 1.5.2 (Patched-1). However this was after I started the quiz. 5 people took the quiz and had the problem, but I had forewarned them so no complaints. The error message occurs after clicking the submit button and getting the results. The results are still visible to me, I just get all the error messages.
Thanks, Shawn