Flat File loading Initialize with out Data transfer is disabled in BI 7.0

Hi experts,

When loading through flat file in BI 7.0 for Info Package Level Initialization Delta Process with data Transfer is coming by default,but when i want to select Initialization Delta Process without Data transfer is disabled. (in the creation of Data Source (flat file) in the Extraction Tab Delta Process is changed to FIL1 Delta Data (Delta Images).

please provide me Solution.

regards

Subba reddy.