How does one delete an incorrect Apply To Funds transaction

OK, a really silly mistake, and the passage of time, is causing me some headaches.

I billed a client one amount, and used the Automatically apply to AR function. I then (in TM) recorded the deposit from the Trust to the operating account.  The only problem is that I wrote the check from the Trust to the Operating account for about 7 dollars less than the amount I should have.  I have deleted the deposit to the operating account, and deleted the check from the trust account, but I cannot delete the Apply to AR transaction.  Is there a way to delete this transaction so that I can go back and record everything properly?  I would like to record 2 transaction that add up to the proper amount.

I forgot to mention that I am using TM8/BM8.

Did you try deleting the invoice?

I did.  Unfortunately, I recieve the error "This invoice cannot be Deleted or Voided because other Transactions...have been applied..."  The only other transaction that I believe is the Withdraw Funds.  When I try to delete that I don't get an error message, it just doesn't delete.