Fixed in V2.0.
Will not fix it in 1.5
Note : Joomla have an issue when ordering = 0, the arrows are not working very well.
Because I do not want to override the whole Joomla Framework (too much already ...), this issue with 0, will remain.
Set up 1, 2, 3, save the ordering, then the arrows are working.
At least in V2.0.
Topic Closed.