I made a general price update in Oscommerce by setting in Localization - Currencies:
US Dollar (default) USD 1.10000002. This price update of 10% shows well in my orders however 2checkout system does not bill customer this price increase.
On orders payed by PayPal I do not have this problem as they process the transaction with this increase charging same amount as is shown on my orders.

2checkout replies:
Thank you for contacting 2Checkout.com, I apologize for any delay or inconvenience you may have experienced. The reason this works for PayPal is because the cart you are using passes the product price and shipping charge as two separate values, which are added together on the PayPal side to form the total. When working with 2Checkout you need to pass the final total that you want the customer to pay. On you cart's confirmation, just before I am sent to 2Checkout, it is displaying the product price and shipping correctly (for my test order the product costs $25.30 and shipping is $9.90) but the amount being sent to our purchase routine using the x_amount parameter is 32.00 (it should be 35.20). Your cart will need to send the correct total for the order for our purchase routine to bill the customer that amount.

My suggestion is to contact the developers of your shopping cart software and discuss with them if there are any solutions to the total price discrepancy. The developers of this software may have updates and patches that will address your concerns.

ANY HELP ?????