Cisco VPN Host Name Issue

We are running Cisco VPN Client version 5.0.01.0600 on several Windows XP SP2 machines at satellite offices. A couple of times each month, when logging on to the VPN, the users get an error message of “Error 5:No hostname exists for this connection entry”. I either have to instruct the users on how to reenter or Netmeeting them to do it myself.

How or why does it keep losing the host name on such a regular basis?

Thanks