I don't understand your question about the vendor. But the deposit problem should be an easy fix.

The Deposit Ticket ID is used to group multiple cash receipts into one deposit for the reconciliation. So if you have two deposits getting combined into one entry in the reconciliation screen, that means they have both been given the same deposit ticket ID. All you need to do is go back to the Receive Money screen and edit one of the deposits to give it a unique deposit ticket ID.