by Fernando Oliveira.
I have added this issue to the Moodle Tracker as a "new feature request". I also inlcuded a suggestion on how to go about it, but as stated in the post, the goal of the feature request to get a resubmission system THAT WORKS into Moodle 2.3.
Please VOTE if you see a need for this function so as to help push this along.
The tracker entry can be found here: http://tracker.moodle.org/browse/MDL-36804
To vote, you will need to register in the Tracker and then click on the "vote" link like this:
http://screencast.com/t/RwLIrcWr
Best,
Fernando