delta-load of 0BBP_TD_BID_1

Hey, experts!

I have the problem with delta-extraction for  datasource 0BBP_TD_BID_1. Hep me to solve this  problem please.

I have observed that the following scenario works:

1. Header and Item data (Bid invitation) were loaded by initialization;
2. Bid invitation status was changed;
3. Standard SAP delta-load brings only the Bid Invitation Header, and  doesn't bring records for Bid Invitation  Items. As a result Bid Invitation Header has new status in the DSO whereas  Bid Invitation Items statuses remained unchanged. . 

In case of full-load, Item and Header data has new changed status.

Thank you very much!

Best regards,

Lyudmila