Dig resolves name, but some applications can't
 

I have an Ubuntu 9.10 system trying to get access to some other machines on the same lan. Dig and nslookup can resolve the names of the other machines, but applications like ssh and autofs cannot. Ssh, for instance, fails with "Name or service not known"

A router running DD-WRT is running the name server. However, all the other machines on the LAN work fine - they can ssh anywhere. Resolv.conf has the following lines:

domain <a domain>
search <same domain>
nameserver 192.168.1.1

However, another machine, running Ubuntu 9.04, has the same resolv.conf and works fine.

What is the reason that some applications on this machine cannot resolve names?

You should check /etc/nsswitch.conf to see if the "hosts" line contains:
Regards