Multiple Fedex Packages

Hello, I’ve run into a problem with Navision eship where it is not attaching the correct values to different packages when shipping with Fedex. I will 1) Open a sales order 2) Pick some items from that order 3) Close the package (//cp) 4) Pick some other items 5) Try to close the order (//cp) At stage 5 I get a message saying that “The Calculation Value cannot be 0 for Package No.=”. All the items have associated unit prices. This doesn’t happen if I ship everything in one package or if I close the sales order first, then re-open it to ship the new package. It also doesn’t happen with UPS or other shipping agents. Anyone know what’s going on?