Every once in a while i will try to enter a payment through the path

Accounts Receivable, cash receipts entry

and the invoice I want to pay will show a zero balance. If i simultaneously pull the invoice up using the path

Accounts Receivable, customer inquiry (or AR, Invoice History inquiry) 

the correct balance will show. 

I can enter the amount being paid, which prompts an alert verifying if i want to overpay. Once i post the "overpayment" the  customer inquiry (or AR, Invoice History inquiry) will show a zero balance but the cash receipts entry will always show the invoice as overpaid. 

Anyone else having this issue or know what is causing it or how to correct it?