Setting the price of an Order Product using a script

Hi, 

I have a script that creates and updates Order Products and I am setting the field "ispriceoverridden" to "true",

but when the Order Product is created/updated the "Total Amount" for the product is 0 (this happens only when the Product of the Order Product has no Price List Item for it).

Still, in the case when I have a Price List Item for a Product, when I try to change the Price Per Unit field in CRM for an Order Product, the Total Amount is not recalculated automatically and the price from the Price List Item remains (maybe that is somewhat related to the above problem).

What could be the reason for the price to be 0 - is it a setting or a code problem and how can it be fixed?

Thanks.

Best regards,

Evgeni Dyulgerov