0HR_PY_1 payroll DataSource with DELTA mode

Hello,

does anybody know, how to implement the delta mode for the business content datasource 0HR_PY_1 (payroll)?

The init-run works without any problems. Than we changed just one record in the source system. But the following delta-extraction (rsa3, psa doen't matter) doesn't extract the changed record.

Please help and get points.