I am trying to reverse an NSF cheque from the bank rec. However, I have posted 2 cheques to the customer as one amount but only 1 of the cheques was NSF. The bank rec will not allow me to change the amount. What is the best way to deal with this?

After a discussion, we decided that the best option is to reverse the "cheque" (which is really 2 cheques combined) and then re-enter the single cheque that was processed successfully by the bank.

It turns out that their previous software wouldn't allow 2 cheques from the same customer to be recorded as separate entries; they had to be totalled and entered as one transaction. Adagio doesn't have that restriction so this situation won't arise in the future,