An interesting question came up to the newsgroup yesterday, it was a case that the the user is trying to create manual payment using credit card option, but the distribution of the manual payment was crediting and debiting the accounts payable account.
That's correct, actually the normal distribution for the Manual Payment is Crediting the Cash Account and Debiting the Account Payables the AP account is loaded from the Vendor account setup selected in your manual payment, and cash account is loaded from the selected checkbook.
Credit ---> Cash ---> Loaded from the selected Checkbook Cash Account
Debit ---> AP ---> Loaded from the selected From Vendor account setup
However when using the Credit Card Option, the cash account loaded will be the AP account of the credit card vendor:
Just make sure that your credit card vendor setup does not use the AP account as account payable, instead use a cash account to fulfill your needs.