MD4C: No reservations relevant to MRP exist for the project.

Dears,

Scenario: Creating Production Orders (MD4C) in ETO case of IDES.

On the "Multilevel Order Report" screen, click the "WBS Element" tab and make an input in the field of "WBS Element", the system issued a message: No reservations relevant to MRP exist for the project. Actually the reservations for T-20600 and P-100 do exist. Does anyone know how to solve this problem? Thx!