Alright, so I have this ethernet card. It worked. Now it doesn't. What do I do?

No... I'm not that stupid. Here's some details:

It uses dhcp to get it's ip. That's the real problem. When my computer loads, it uses ifup through /etc/rc.d/init.d/network to bring up all the networking devices. For some reason, now it always displays the general help when /etc/...../network is used. But when I just type "dhclient eth0", it works fine. When I use /etc/...../network restart it always fails to bring down the eth0 card. All these functions work fine with my eth1 card, which is a dhcpd for my internal network. Any suggestions on how to fix my eth0 problem would be great.

Thanks,
Atroxic