I have seen a lot of updated modules in OpenERP apps didn't have a new version number.
As an example mass-edit was in september 2012 version 1.1. And the update from 12 April 2013 is still the same version 1.1.
By the way, this is a very nice module to work with!
This issue is not unique, the same is for all Dutch localisation modules.
I find this confusing.
Why is this?