I have three words to say about KVM switches:  Cybex, Cybex, Cybex.  I have
tried everything else just about and have fantastic results with their
entire product line.

One of the monitors in my office is connected to 8 misc servers in a room
200 feet away using a Cybex Autoview Commander and a Cybex Longview KVM
extender.  These include, two linux, one novell, two dos, one win98, and the
rest are NT or 2K.  The mouse and the keyboard switches perfectly on all of
these (although I don't use the mouse on the DOS stations much).

Yes, they are more expensive, but I have a pile of crappy KVMs that would
not do the job.  Even the low-end 4 place cybex units work great and I have
a number of those around here and at home.  Same switch quality as the big
daddy, and of course, it uses the keyboard to make the swtich so you don't
ever have to look at the actual unit.

Also, on the Commander, cybex uses a nifty prefab (expensive) cabling system
that cleans up that mess of cables you usually get with the KVMs.

Just my .02

sj