Negative Encumbrance on Trial Balance

I thought I posted this discussion a week ago, but I can't find it, so i apologize if this is a duplicate......

Upon our monthly reconciliation of the Encumbrance Detail Report to the Encumbrance Trial Balance report, a balance was found on the Encumbrance Trial Balance report which is not showing up on the Encumbrance Detail Report. In the prior two months, the reverse happened - the balance was showing on the Encumbrance Detail Report but not on the Trial Balance report. Our action plan was to close the PO (an old PO that needed to be closed anyway) which would make the balance drop off the Encumbrance Detail Report, therefore clearing any discrepency. However, it appears that caused the reverse to