I may well be the last person still using the original, unmolested, occasionally crashing server version

I have a KC license for all of my machines, but never got it reliably passing extended keys between XP and Vista boxes so I'm still using a bizzare combination of Multiplicity (which I use even when I'm not boxing), Multibox and when I need to run more than one WoW on a machine I fire up KC as well (just on that machine)!