SIP Communications Service failed


I got this error:

Signing in to SIP Communications Service failed because the sign-in
name, username, or password is incorrect, or the authentication service
is not compatible with this version of the program. If you have signed
in correctly and the problem persists, contact your network
administrator.

But, this only occurs to my PC. when i connect my account to another
PC, it works just fine, so i don't think it is an LCS configuration
matters. Previously it works, it is hard for me to chat with my
colleagues internally w/o my SIP working, using my PC. Help???

Btw, my OS is XP Professional SP2, Windows Messenger v5.1


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aerwynah
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