Unable to update custom fields added to MAW1 via IDOC

Hello.
I have added 2 custom fields to the table MAW1 and added a subscreen to
MM41/42/43. Based on the note 44410 I am successfully able to update
the 2 fields in MAW1 table using MM41/42.
But, I am unable to update the 2 fields using IDOC of type ARTMAS05. I
am passing the values for the 2 fields to the CLIENTEXT and CLIENTEXTX
structures and then evaluating it in the implementation of Method
MODIFY_MMD_DATA of BAdI ARTMAS_BAPI_EXTEND. But the values do not get
updated in MAW1.

Also, the 2 additional fields do not appear in MM46 for mass change. I
have implemented the 2 methods of BAdI BADI_ARTICLE_MASS_RT as per note
925424.

Thanks
Anmol