Credit Card Processing Vtg 8.03.409C

We are a month into our live use of credit cards and would appreciate any input or feedback on the following issues.

First, we have multiple workstations that are unable to process credit card transactions. They use the same security certificate as "working" computers, however, they farkle-up the credit card number (I believe the trouble computers display the encrypted credit card number on the Credit Card screen). Once this happens, the sales order can't be processed (we get the message that the credit card number exceeds 20 characters). We have an open call with Epicor, however, the initial recommendation was to reinstall Windows on the problem machines. Anyone have any experience with this?

Our second question/issue has to do with the way Vantage is processing credit card transactions. Currently, we take orders and Authorize the amount against the customer's credit card. Then we pick the parts, box them up and add a Miscellaneous Charge on the Packing Slip for Freight & Handling (we don't know the freight until we have the parts ready for shipment). On order shipment, Vantage performs the "Deposit" credit card transaction for the Authorized amount and a "Sale" transaction for the add-on charges (which also may include Sales Tax). Is there a way to avoid the multiple transactions, we would prefer to only charge the customer's account once for the total?

Any and all input greatly appreciated!
Sincerely,
Peter Dunbar
Halm Industries Co., Inc.