Here are some ideas:

1) Rather than Manually enter the address, connect using DHCP and let the puter get all its stuff from the server (do this in your System preferences under network).

2) If that does not work, try this. Change from Ethernet to Modem. Hit the apply button. Then change back to ethernet and hit apply (do this in your System preferences under network).

3) If that still does not work, try running the internet setup assistant. This is an app. that is on your mac somewhere. You can use the finder to search for it.

4) If that doesn't work, disable the modem and airport.You can do this in System Preferences under the Network panel. Where it says "Show:" Select Network Port Configurations from the drop down menu. Deselect everything but Etehrnet. Then repeat 1-3.

That should work. Also, check to see if you are getting an IP address. If it starts with 169, that means it's a fake address (ie it isn't connected to anything). If you are getting anything else, you are connected. I find that using DHCP works better than doing the manual configuration.

But that's just me, I'm a different breed of cat.

Peace,

O
B unce!