Invoices with custom amounts fields

I am trying to import some historic invoices where all the amounts do not necessarily correlate to the pricing that we are currently using for items, so I am trying to set the amount field to a custom value. In the Netsuite regular interface, I can do this but I get a warning message indicating that the                            "The line total amount is not equal to the item price times the quantity.  Is this correct?". I have turned off the treat warnings as errors functionality in the user interface for webservices, but I still get a list of error messages with