I had a strange situation where I was setting up a small network all with fixed IPs. I had a NAS drive that I had enabled ftp on. I was using ubuntu 10.10, when I used the 'connect to server' menu I was able to connect fine (or just entering in the URL in nautilus). However from the command line the ftp command didn't work, and gave an unknown host error. I was able to ping the drive however.
In the end I used the gvfs-host command to enable a scripted connection. I'm just wondering if anyone has come across this problem or how to fix it.