Give the gift of Drupal. All merchandise is 50% off through 2016.
Currently, when you clone a Quiz node using the node_clone module (http://drupal.org/project/node_clone) it correctly clones the node, but it loses all of the associated questions. This is far from ideal because the questions are one of the primary aspects of a quiz, and thus it would be expected for the question association to be maintained when cloning a quiz.
I have attached a patch that adds support for transferring the question relationship to the cloned node when saving. In order to test this patch you will need to install the node_clone module.