Thank you, Mike, Nick. I've managed to telnet to the offending machine on port 631 both from its own console and from the other PC on the network. But I don't know what to do next.
I'll look at the logs as you suggest, tomorrow. At this time of the evening I'm dangerous. My RH distro has put some commands into /sbin rather than /user/bin, e.g. service, so it's not much different typing "/etc/init.d/whatever start" from typing "service whatever start". (Caused me much anxiety earlier on in my year-old Linux career when I couldn't find commands I was supposed to have - then I discovered the magic prefix "/sbin/") =====Andrew
