NFREN Out of Range problem

[#1]

Kubuntu 9.04 currently installed. Works fine when Monitor, keyboard and mouse connected direct to computer but when when using KVM Switch I am presented with blank screen and "NFREN Out of Range". I hasten to add that I am new to Linux and experimenting with various distros. Some work OK with the KVM switch and some don't and I assume that problem is the same in all instances.
Any help is welcome.
Mike

[#2]

Try Google.
It seems to be a problem associated with Windows XP - http://www.tomshardware.co.uk/forum/page-25440_35_0.html
Have you set a screen resolution that is too high?
Also see http://www.ubuntux.org/frequency-out-of-range

[#3]

This can happen when you start a machine and the screen isn't connected to it, i.e. you have the KVM conencted to machine 1 and switch on 2. Used to happen regularly when I used a mechanical/or cheap  KVM. These days when I start a machine and it isn't on the KVM I get 800x600 and have to restart the X11 server (Ctl-Alt-Backspace unless it is disabled in xorg.conf)

[#4]

Thank you both for your help.
I am pleased to say that I have been able to solve the problem by having the other computer (running XP) on when booting the Linux machine. As I said earlier I am trying out various distros and have 3 harddrives each with a different version! One of the three booted OK without the other machine on which I found most odd and researching this on the net did not provide me with a solution hence my call for help.
Mike