hosts: files mdns4_minimal [NOTFOUND=return] dns mdns4
which means looks up check hosts, mdns and if mdns reports a not found then it doesn't go to DNS.
Switching it to
hosts: files dns mdns4_minimal [NOTFOUND=return] mdns4
fixes it by having DNS get checked first. IMO this should be the out-of-the-box configuration since the historical trend would be the DNS is serving names and should get precedence anyway.
Just ran into this myself with 12.04.
The problem is nsswitch.conf is:
hosts: files mdns4_minimal [NOTFOUND=return] dns mdns4
which means looks up check hosts, mdns and if mdns reports a not found then it doesn't go to DNS.
Switching it to
hosts: files dns mdns4_minimal [NOTFOUND=return] mdns4
fixes it by having DNS get checked first. IMO this should be the out-of-the-box configuration since the historical trend would be the DNS is serving names and should get precedence anyway.