I just noticed my template is not acting the way it should... for +- 10000 products the media file ( virtuemart_medias ) contains now +500 000 lines !!!
The problem is : I just want to copy the files on the local server with the media import template and, unfortunately, it is adding lines to the media files in the database each time I run it.
What did I do wrong in the set-up ?

Is there a model in the documentation ?
Regards
Eric