ubuntu on vmware: network is unreachable

Crap, yesterday my Ubuntu 10.4 on VMPlayer was working ALMOST filne,
today I get "network is unreachable" whenever I ping anything.
My VM is set to use NAT.

I do:

cat /etc/network/interfaces

auto lo
iface lo inet loopback


hey, where is eth0?

Here some example, so I "chmod 777" and I add to the file:

auto eth0
iface eth0 inet dhcp


and I
sudo /etc/init.d/networking restart
(it takes a while)

(same can be done with the menu Preferences/Network)

This seems to take care of some issues.