thanks for the link. I tried to access the quiz, but it seems I need username to enter your site. Could you set one up for me and send the details to me at:
gordon at-sign kanazawa hyphen gu dot ac dot jp
By the way, do you have any other hotpot quizzes that are working OK on your site?
Finally, one thing you might like to check is that you have the latest version of the HotPot module for your Moodle site. You appear to have Moodle 1.5, so I recommend you download the latest stable version of the HotPot module: