Service contract not updated with invoice number

Hi all,

We have an issue.

1) We have a contract and push it to AR interface, by running 'Service Contracts Main Billing'

2) We update the interface attributes( interface line attributes 1-12) with values we need to see in the invoice (  by overriding what Service Contracts Main Billing program populates) in AR interface

3) Then we run Auto invoice in AR and the invoice gets generated

4) Now, when I run the 'Service Contracts Fetch Receivables Info for Billing' program, it does not update the contract with the invoice number in AR.

Is it because of the interface line attribute update that we are doing in the AR interface? If yes, how do we get the right invoice number updated in the contract? Please note that we cannot have the interface attributes populated by the standard program.