Hi,
When I run the program in the background, it posts only for one purchase order.
When I run the program in the foreground, using the Select All-button it only proceeds with the first line in my list of PO's.
See..it's a Z-program so Its difficult to answer without checking the program. But I think, you should check your BDC again from Debugging, with the help of your abaper. You will find, why its is processing only one entry.
Regards
Shishir