OracleShipping 11.5.10,2- Backorder selective order lines does not work-api

 Hello,

I need to backorder only the lines with shipped quantity 0 and ship confirm remaining order lines in a given sales order.  There is no ship set and fulfillment sets.   And I need to backorder only few lines and not all using API.  It works as expected through form.    For example if a sales order has 2 lines and line 1 is back ordered,  then it should show status as "Backordered" for Line 1 and "Closed" for line 2 in  delivery transaction screen.  Instead, the API backorders both lines.

Please let me know what am I missing in following code.  As per metalink note# 1340858.1,  the action flag B stands for ship entered qty and back order unspecified.  But when I specify value as B in action flag in below mentioned code, it is backordering entire order.