Error Order was not placed

[size=4][font=arial,helvetica,sans-serif]When a customer is done paying for an order in Google Checkout, they have the option to return to the shopping website (can't remember the exact phrasing). When they click ok, they get sent back to their cart with an error that reads “[color=#555555]Error Order was not placed.”[/color][/font][/size]

[size=4][font=arial,helvetica,sans-serif][color=#555555]The order was placed, however. It arrives as open or processed. Everyone gets confirmation emails. All is good. Except for the error.[/color][/font][/size]