Import Csv ignores default combination if a previous one is set

[smythsys]

Hi,

   We have a problem when importing products with combinations to our Prestashop (1.6.0.14). When we first import the products it takes our import correctly and sets one of the combinations as default (lets say combination A).

 

Then while selling combination A might go out of stock. So B is set as default. 

 

If we then do another import (we do one every 1-2 days to synchronize the web with our local CRM), if we again set product A (or even C) as default in the import Prestashop ignores this and keeps B as default.

 

¿Can we do something? Can someone help?

 

We've tried to put B as not default and A as default on the second import csv file but that didn't work either.

 

Thanks in advance.