R12 EBS Invoice Accounting Flow in Encumbrance Environment

Hello,

We are upgrading to R12 from 11i and we have a custom report that looks at encumbrances in table ap_encumbrance_lines_all.  In R12, I see this table still exists but data is not being populated in this table.  Has there been a change in where the encumbrance and reversal transaction data is stored for R12?  I'm looking at the encumbrance when a PO is open and no matching invoice has been created and then expecting a reversal in encumbrance when the Invoice is created, matched and Approved.  I was expecting to see the encumbrance details in ap_encumbrance_details_all table but the transaction