I assume you ran the nic_install script. How are you getting your IP address? DHCP or static? Check the rc.net file which sets these parameters. Make sure you don't set ip addresses in rc.sysinit.author. Also, try a known good ethernet cable.
Oh, and to set it up for the daily call over the internet, I believe you have to set ",#401" (w/out quotes) as the dialing prefix in the phone options.