Inbound Idoc L_IDOC_INPUT_WMMBXY - duplicated lines in material document

Dear All,

We have a non SAP WMS system and we use Idoc to communicate between
systems. For 301 movement type I receive an inbound Idoc in SAP system (message
type WMMBXY, process code WMMB, function module L_IDOC_INPUT_WMMBXY). I have
write code in 2 user exits: ZXMBCU10 (EXIT_SAPMM07M_010) I populate e_charg
with * (in this way the system will automatically call VB_BATCH_DETERMINATION)
and ZXVBZU11 (EXIT_SAPLV01F_002) I set c_bdcom-nodia = 'X' in order
to deactivate VB_BATCH_DETERMINATION dialog mode.

The problem is that when I process an inbound Idoc – the lines
are duplicated in the material document. The segments in Idoc are ok.

Have you any information about this? Could be a SAP system
bug?

Regards,

Florina Rau