Access Permission issue

I’m keep getting this following error message:

\\server\My Documents is not accessible. You might not have permission to use this network resource. contact the administrator of this server to find out if you have access permissions.

The network path was not found.

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I have full right accessing the folder. One in a while, I’ll get this error. I’ve looked into Event Viewer; there is no error log showing I’m being disconnected. I went to DOS command prompt and ping the server, I got respond back. After pinging, I’m able to access the folder right away. Very interesting enough is maybe few minutes or hours (randomly), I’ll get the follow error message again.

I’m currently join in the w2k domain.

Does anyone know howto solve this issue?