Comment 18 for bug 203593

(Not sure where to add this, but the title of this bug sounds appropriate enough):

I have been using OpenVPN and though I was not connected to my VPN during update from 9 to 10.04, I was not able to resolve hostnames. The conditions were

-wireless showing great signal and proper DNS
-able to connect to IP of router providing DHCP
-unable to ping openDNS or google DNS directly (e.g. 8.8.8.8 did not work)
-restart did not work
-/etc/hosts was clean

I did notice during pinging that it tried to resolve addresses via 10.x.x.x, which is what my VPN uses, despite not having started the service.

Resolved by finding the process with ps and then killing it. All is well.
cheers