Running 4.5.2. Just noticed this one today.
When a customer makes a partial payment on an overdue invoice, the invoice itself correctly shows a remaining balance, however the invoice no longer shows up in the overdue invoice list. That makes it easy for our accounting people to lose track of those invoices and can allow a customer to skate by without ever paying the remaining balance.
Not the end of the world, but something that should be addressed.
FWIW, the invoice does continue to show up in the unpaid invoice list, so we'll have our accounting group check that list instead.