Contract Billing - Releasing RETN and Invoicing in same batch

Hello,

One of my users wants to know if the following type of scenario can be done.

She wants to be able to create 1  invoice to Release existing RETN on a contract and at the same time, add a new line of additional charges.

I tested and here are my steps.

1) Manually create a batch

2) Manually create an invoice within this batch.

3) Perform the Release the RETN steps

4) Select the billing line for the additional charges

5) System allows all these steps, but when I go to create the A/R - my R48300 is failing due to the extra invoicing $$ not getting allocated.