Thanks Jamie, That's good news !
My intention is to make clear in the text for the plugin database to give due credits to all contributors of this wonderful Moodle activity plugin.
I am still fighting a bug : when a student delete a question that was already graded the new calculated grade is wrong until a teacher garde or regrade a question created by this student, but once this is fixed I think that if I don't find any other problem the plugin will be ready for a first release.
According to my tests the version for Moodle 1.9 have the same problem if a student delete a graded question.
I will try to contact Peter and Exabis.