Hi All,
Sorry for the late update , Just posting the solution to close the thread.
Guys this was coming up because in BBP_Pd the value of invoice is updated in the table bbp-pdigp and as we are using Service PO's in SRM 5 there was a fault in the system where the multiple line items confirmation & invoice value was getting posted in all the line items of the PO.
for ex - each line item has value 10 and there are 5 line items then each line item conf & inv was getting updated as 50 (10*5) making the total conf & inv value as 50*5 = 250 where it should be only total 50.
that was the reason when we were trying to uplift the line item 1 this error was coming up as line item was already updated & calculated.
This was because as u all know in ECC the service entry sheet has mainly one line items and its sub line items.
Issue was solved by SAP has created 1 note for SRM and ECC by which the view was corrected and the values started getting updated correctly aganist each line item.
Thanks
Sudhir