TAX_GROUP_BP_01 field in quotation in SAP CRM system is not updating at all

Hi,

when we create quotation in SAP CRM...there is tax conditon type in item level...where it has the field TAX_GROUP_BP_01...and this field value is not getting updated at all..Could you please anyone suggest us why this value is not updating in CRM system

Thanks and Regards,

Sudhansu.