How can I setting DNS server?

I install angstrom in my BB.
and I set DNS server using Network Setup(Xwindow menu).
and I conform configuration in /etc/resolv.conf
cat /etc/resolv.conf

but I reboot my bb. That configuration is removed( /etc/resolv.conf).
How can I fix my configuration?

Have a nice day...

Take a look at:

My first guess is that the DHCP client is running (udhcpc) and that could be erasing your /etc/resolv.conf.