Hi Elhoussiny,
As Siddhartha says, AIE delta mode is not designed for DSO's. The problem might be generating after running your first delta load after the initial one. "Cube OK" suggests us so.
One way to test would be: 1) Delete your dso's data and clear delta initialization (edit infopackage > Scheduler menu > Initialization options for source system > delete initial selections) , 2) Create and execute "initialize delta with data transfer" infopackage, and check your data. ¿Discrepancies? => Something wrong with extraction (this scenario is 99.9% discarded), ¿OK? => Proceed to 3.... 3) When new records or changes to existing records are available in source system, execute a "delta" infopackage and check again your data. If you find data discrepancies the theory will be confirmed.
Regards,
Fernando