Customer has to manually add discount on customer order lines if we use the customers part no instead if the sales part no when Use Price Include Tax check box is checked.

Test Plan:
1. Prerequisite is to have an external customer, which has the Use Price Incl Tax checkbox selected as Tax Calculation Basis for the company in Customer/Order/General tab.
A Sales Part exists and also a Sales Part Cross Reference record against the customer.
2. Create a new CO header and see that the Use Price Incl Tax checkbox is selected in the Misc Order Info tab.
3. Start entering a new CO line and here it can be seen that the Discount % shows as 0 already when pressing New. Here choose to add the Customer´s Part No through the LOV, which will then automatically retrieve the Sales Part No, and at this stage the Discount % is removed. Enter the Sales Qty and save. See that still the Discount % is NULL and hence the system will raise the error

"The field iDiscount %] must have a value"

4. Now start over and instead enter the Sales Part No instead. This will retrieve the Customer´s Part No and after entering the Sales Qty the system will also again set the Discount % to 0. So here it works fine to save the CO line.

The expected behavior is that also in step 3 the system should retrieve the Discount % as 0 and it should not be necessary that the user manually enters the value.

This problem does not exist in UPD9, but has been introduced from UPD10. It is not clear which bug has caused this problem.

Workaround is to manually add the discount %