Signal out of rangee time

[Beartooth]

	I'm getting an ancient horror message from my old HP w2207h flat 
panel monitor. I have a KVM switch between it and three different PCs, of 
which the newest (#1) is running F23, the oldest (#3) F22, and the middle 
F22 or F23 (I disremember which).

	About the time any of them finishes booting, the HP immediately 
slaps up a box over the top of the login box, complaining that the signal 
is out of range, and goes black.  

	This monitor used to exercise this perversity when it was new, and
it was a real bear (not to say a mother) to correct. If I recall aright, 
you had to get into xorg.conf somehow, guess the changes it wanted (and 
where it wanted them), make those changes, and reboot.

	That was years ago, and hasn't xorg.conf bitten the cyber-dust 
long since? PCs # 1 & 2 have been peacefully running Fedora; I think #3 
still has CentOS 6, but will switch to F23 as soon as I can get to it.