Thanks to all who pointed out this was a hardweare problem. I changed the NIC and it works better now.
I can telnet into the linux box. The linux box can do all the internet type stuff so both NICs are working. The uptput of ipfwadm -F -l is type prot source destination ports acc/m all 10.0.0.0/24 anywhere n/a which is fine. But the PCs on the LAN cannot ping the public IP of the server let alone access the internet. Help please. Why am I unable to give internet access to my machines on the LAN? Patrick