Hi Rama,
You need to debug it further.
The addr might be changed back to that in BUT000 in following 2 phases.
1, address and BP is mapped in this form when uploading to ecc. the name and addr might be changed to that in BUT000 before it is in ECC.
CRM_R3_SALESDOCUMENT_UPLOAD ->
CRM_SALESDOC_MAP_MBDOC2BAPI ->
PERFORM fill_bapi_parnr_and_addr1
2, the name and addr is not changed in mapping from bdoc to bapi, the 1-time changed name and addr should be in bapi and uploaded to ecc. Then the SD create/change will be called. You may F6/go to the next statement to run the create/chagne and check if the partner name and addr is chagned to BUT000.
CRM_R3_SALESDOCUMENT_UPLOAD ->
RFC call BAPI_SALESDOCU_PROXY_UPLOAD ->
SD_SALESDOCUMENT_CREATE or SDSALESDOCUMENT_CHANGE
3, the data in ecc will be replicated back to crm. the BP name and addr will be mapped from bapi to bdoc in crm_salesdoc_map_bapi2mbdoc.
The whole debugging is complicated. If you cannot do it yourself, please raise an incident with detailed steps. Put it to crm-btx-bf-if.
Spencer