Bapi_Material_Savedata invoking through webservice, can anyone help me?

I received error messages bellow:

MG Field MATNR has been transferred inconsistently or is blank

MG MATNR for LTX1 is ""; previously "000000000030000917"

MK Trying to change: 30000917 ____ ____ ____ __________ ____ __ ___ ___

The following parameters are passed:

MATHEAD.MATERIAL = "000000000030000917";

MATHEAD.IND_SECTOR = "C";

MATHEAD.MATL_TYPE = "ZFRT";

MATHEAD.BASIC_VIEW = "X";

MAKT[0].LANGU_ISO = "ZH";

MAKT[0].MATL_DESC = "MATE NAME";

MARA.MATL_GROUP = "0001";

MARA.BASE_UOM_ISO = "KGM";

MARAX.MATL_GROUP = "X";

MARAX.BASE_UOM_ISO = "X";

These parameters are passed testing in an ABAP Report Program which calls the BAPI.

I don't know what's the problem, can anyone help me?