Duel Modem and Nic Connections

Hi all. I have a wee problem with a new Dell Insparon 4000. It has onboard nic and modem built in. It is running win2k, 128Mb ram 5Gb HDD etc. I can set up the local machine to run on the modem without a problem, connects every time, the user has admin rights only on the local machine. When I set up the network connections, give the user power user rights on the network, see all the other workstations etc. The modem connection has issues when logged in under the local machine. errors like 732, 718, 735. Then all of a sudden it will connect without any changes being made. Has anyone else had this problem? The network is set to auto detect IP's if it is of any relevance.

Thanks in advance.

If it is a workstation Disable the Modem wile connecting with the NIC.
Also Apply SP2

Thanks for that, the problem isn't the nic it is the modem, the nic is disabled under the local machine logon and Sp2 is installed.