Transport cost not calculated

Hello,

This might sound strange, but I am facing this issue.

In shipment document, when I check the Freight Cost Estimate option, system shows freight calulated based on the condition records maintaiend in TK11. However, when I create a Shipment Cost Document for this, there is a error Shipment costs $0001 item 000001 cannot be transferred (value 0). The cost Item net value is zero in this case, whereas when I check the estimate in shipment document it is 147.00 GBP.

Any inputs, why this is occuring ?