I have many vendors that bill us on a weekly basis, so I found that it was quicker with this to load the invoices through an import.  Before the upgrade, I knew that it was possible to load a duplicate invoice number for a specific vendor and had accepted that as a possible downfall - so if I received an invoice that wasn't current, I would verify before including on the import. 

After the upgrade, if I am trying to load an invoice # that has previously been entered for any vendor - it will not import - and I get the failure message "A record with this ID already exists. You must enter a unique ID in order to create or update this record".   Because we utilize a substantial number of small subcontractors - who number sequentially on their invoices - we do have a lot of duplications in the low numbers.  Anybody else affected by this?  Is there a work around?