Ship-to-party field should be editable for a sales order with completed status in CRMD_ORDER

hi experts,

we were upgraded our CRM system from 4.0  to 7.0 ehp1.

For a  sales order with status 'completed' ,Ship- to party field is editable in

CRMD_ORDER  TCODE when we click on edit icon in Old version.

But it is not working same as above in new system.

How to make ship-to party editable in new version..

Please help me ASAP.

Thanks,

Usha