Listed below are reasons why the Item Rate changes when a Purchase Order is Edited.
1) The PO rate changes depending on the Purchase Price set on the Vendor, Last Purchase Price or Purchase Price in the Item record.
2) If an item has a preferred vendor setup (Basic tab) and has a purchase price set for that vendor, the system will pull up the preferred vendor's purchase price rate when you changed the vendor name.
3) If an item has a preferred vendor setup (Basic tab) but has no purchase price set for that vendor, the system will pull up the purchase price rate found at the Inventory tab when you changed the vendor name.
4) If an item has no preferred vendor setup, it will pull up the purchase price rate found at the Inventory tab when you changed the vendor name.