[CentOS] The most weird thing i've ever seen (networking)

Hi,

I've installed a mail server using CentOS 4.4

Now, if i reboot the server remotely by ssh, when it cames up, i have no 
network.
The interface is up and everything looks pretty fine.
But i can't even ping other machines in the same intranet.

If i reboot it locally at the console, the network cames just fine.

Never seen nothing like this.

The mind boggles :(

Any ideas ?

Warm Regards,
Mário Gamito