Before when editing a payment, we only listed the invoices which that payment was applied to. The problem is, if you accidentally saved a payment without allocating it, and then went back to try and apply it against an invoice, the system wouldn't let you. With this update, we now list all open invoices when editing a payment, allowing you to allocate against them! Enjoy :)
UPDATE: We have temporarily disabled this new improvement ... it will be back! Not to worry. We just discovered a few oddities with the new behaviour!
UPDATE X2: This new functionality is back again!! As always, we look forward to your feedback!