Hi Lluis,
Nice to see again!! I've never stopped to fight with Solman ;-)
I have checked this field but it does not solve my problem, host and database is with sold-to party empty. You can check this in Technical monitoring->System Monitoring and in host or database tab open monitoring and you will see Sold-To Party with no values...
The SAP note you refer are 1957919 - Business Partner Assignment to a Product System is not saved.
and 1954334 - Logical Components loses the assignment to Business Partner in the LMDB editor
both do not apply to my system
Regards.
Jose