I need help about a problem I met after importing my customers data in Magento.
I imported the data via csv to a new magento in order to create a new website, but I met a problem concerning the customer groups.
I cannot find the reason why but for some customers account, after saving their data, they are changed from the "domestic market customer group" to the "overseas customer group".
From what I was able to check, It seems there is nothing in common between the customer accounts that are changed from one group to another.
Would anybody know why this is happening?