Trouble Connecting Via Ethernet Cable

Hello,

I have a Belkin 802.11g modem and using wireless I can access the internet but when I plug directly into the modem using an Ethernet cable it does not work at all.
It worked beautifully when I was connected to another service provider but have recently changed and i am wondering if there is something in the modem setting that needs to be configured as well to allow me to connect directly to the modem???

Please Help

Cheers
Tom