MDG-S: Warning on custom reuse area data when modifying supplier

Hi experts,

I have followed the link below to create a custom reuse area to read/write data on Z tables for my custom entities using an access class (an CL_MDG_BS_BP_ACCESS_MASTER subclass) and I have assigned it to the new reuse area.

http://scn.sap.com/community/mdm/master-data-governance/blog/2014/03/21/master-data-governance-custom-data-model-implementation--re-use-mode

All is working right and when a supplier is displayed the data stored on Z tables is assigned to the UI. But, when I modify the supplier, the previous data is lost and a warning message USMD1A 204 is raised for each field:

How can I do to don't lose the previous data and the warning message will not be raised?.

Thanks in advance.

Best regards,

Jordi