take care of use of $node where &$node is needed

trying to track down a bug in my install make me read again all the code and i have a little note about it : according to http://drupal.org/node/40684 $node parameter should be passed by reference and not by value in some functions. so :
multichoice_insert(&$node)
multichoice_delete(&$node)
quiz_insert(&$node)
quiz_delete($node) ...
further reading at http://api.drupal.org/api/4.7/function/hook_form and http://api.drupal.org/api/4.7/function/hook_delete

i do not provide a patch (sorry, i'm very busy and a bug in my drupal is driving me to a headhache) :)