Documents button on purchase line shows different form

In previous releases, when you clicked the Documents button on the Purchase lines for parts form (Purchasing module > Lines button) to retrieve documents, the destination of the purchase line determined the documents displayed:

From Isah version 4.6.2, clicking the Documents button will always retrieve documents linked to the purchase line. To view the documents linked to the sales line, use Lookup from the Sales line field on the purchase line to open the Sales lines form, and then click the Documents button. To view the documents linked to the production calculation line, click Lookup in the Calculation line field, and then click the Documents button.