Processing Inbound IDOC - Function module IDOC_INPUT_INVOIC_MRM ?!?!

Hi experts,

I created a copy from IDOC_INPUT_INVOIC_MRM(function module to process the inbound idoc with idoc type INVOIC01) to Z_IDOC_INPUT_INVOIC_MRM .

I used 2 transactions:

>BD51 - Maintain Attributes

>WE57 - Assign IDoc Type and Message Type

for this new function module.

Next step, I tested function module Z_IDOC_INPUT_INVOIC_MRM by use the transaction we19. The invoice was not generated the same of testing with function module IDOC_INPUT_INVOIC_MRM.

Anyone can tell me why?

(2 functions module is the same source code)

Thanks,

Gy