network trouble: dhcp works, resolv.conf correct, ping doesn't work

["Owen Heisler" <owenh000@gmail.com>]

I'm having trouble with the internet connection on a Lenny/Sid system.
 It is a very simple connection to a cable modem via an ethernet
cable.

/etc/network/interfaces includes the lo interface and "iface eth0 inet dhcp".

"ifup eth0" seems to work: the dhcp server (cable modem) gives the
correct IP address.

For some reason, at this point, iptables (I don't use a firewall)
starts spitting out a bunch of junk... (if you want to see it say).  I
run "iptables -F" to stop that (removes some "log" stuff), but it only
works until a reboot.

/etc/resolv.conf is correct.

"ping google.com" returns "unknown host".

It all works when I boot the GRML LiveCD.

Thanks for your help.