Dear Sudheer
You are telling same material in 2 line items means so same item category no issue in item category
And check in second line item Material Schedul line Dates are updated same like first line item and second line item
So i hope you have to run The programes
RVKRED88 ,rvkred77 OR check_cm
plz run the programes with abapers
http://scn.sap.com/docs/DOC-50996
plz let me know
