There was question about why we created 3 invoice for "Drop ship sales order across OU" in reference to my post http://eoracleapps.blogspot.com/2010/11/how-to-create-drop-ship-sales-order.html
For More details about Drop Ship across OU , please refer the POST
Please Note that ,as per Inter-company Setup , System will generate 3 invoices.
1.AR Invoice from US Operating Unit to Customer..
2. Intercompany AR invoice in Singapore OU(Shipping OU) to US OU(Selling OU).
3.And now US has to pay Singapore OU, so an Intercompany AP invoice will be created in US OU .
US OU - Selling Operating Unit
Singapore OU - Shipping OU
Hope that will helps