Thanks Anthony,
First we tryed placing the series resistor with the boot capacitor but without success: this solution did not solve our problem.
Then we followed your suggestions and added a Snubber filter into our circuit, causing the results to perform better than the last tests did. Even so, this is not quite what we are looking for...
Now we are thinking about an optimize design using a smaller package diode to see if the ringing effect is going to decrease and therefore eliminate the inclusion of the Snubber Circuit.
Any new results we achieve, I'll be sharing here.
Thanks and Best Regards,
Fernando