0material Delta upload 0 records

Dear experts,

i'm looking for a solution on 0material_arrt delta uploading.

details as follows:

1.created an init infopackage(initialization with data transfer);

2.run the init infopackage(got records);

3.created 3 new materials in ecc;

4.checked the datasource using RSA3 in ecc and newly created materials can be found;

5.created a delta infopackage;

6.run the delta infopackage;

BUT, the delta request contains 0 records.

so, anyone could help me on this matter.

thanks very much!

neal