In Yahoo Messenger Error Code-40402 Address Book?

Almost 9 out of 10 times, when I am trying to update address book of my Yahoo Messenger Contacts ( like adding mobile number or nick name , etc ), I get the above error code, and my updation is not accepted.
Please advise.
I am using YM 8.1.
Thanks in advance to all
Update: Pls explain what you mean by:
" try editing your contacts details in your address book before editing messenger contact information"
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