Duplicate charge and settlement but no Receipt created.

Hi ,
We are using paymentech as our payment processor, we do authorization at the time of pick release and settlement at the time of remittance creation. Here is the situation we are running into.

We have a sales order#314054,for $225,created on 18-Mar-2011,with payment term credit card and is due "In advance". The invoice and receipt got created on 18-Mar-2011 and we could see , Oracle Payments, the authorization record and settlement batches created on 18-Mar-2011.

However strangely on 30-Mar-2011, when we run the settlement batch program, the program created a credit card charge for the same amount $225 and we could see that settlement batch was referring to the same order number #314054, although another receipt was not created. I am surprised how come a duplicate charge like this is created and also without a receipt.