Cancel Shipment Functionality

Hello:

We are upgrading to R12 from 11.5.10.2.  In 11.5.10.2, when you cancelled shipping in DTS, you still needed to manually update the qty.  In R12, when we cancel shipping, the qty is automatically update.  Our users do not like this change.  Can someone confirm on Cancel Shipping should be functioning and why it changed from 11.5.10.2 to R12.  Also, I would appreciate someone pointing me to the documentation that specifically states what should be happening during the cancel shipping execution.

Thanks,

Susan