Error Matching PO with Multiple PO lines to an Invoice

 I have successfully created PO's and matched them to Invoices.  However following the same steps but including more than one PO line on the PO causes my match to be successful but then invoice validation fails.  When I look at the hold reason it states "Encumbrance Accounting Failure".  I tried using small amounts and tried changing my buyer but nothing seems to work.  Has anyone run into this issue or found a workaround?