I am new to eConnect/GP and am using version 9.  I am attempting to update purchase orders in GP once they have been received.  This works fine in most cases, but one thing I've noticed is that if you simulatneously send up two line items (taPopRcptLineInsert) from the same order that have identical item numbers, even though they have different line numbers (RCPTLNNM), eConnect issues the error "Input variable contains a duplicate document (POPRCTNM)".  If the items are different there is no problem.  GP does allow users to add the same items with the same item number on separate detail lines for a purchase order, so I'm not sure why eConnect would have a problem with this.  Any ideas?

You'll need to specify the Line number of the item that you're matching. I think the field is ShipRCPTLNNM

Right, I am setting the RCPTLNNMs, which are different for each. But for some reason eConnect seems to think it's a duplicate based on the fact that they are identical item numbers (even though they're on separate line numbers) for the same purchase order.