If you want to keep your Macs and Xserves up and running, especially in case of a power outage - then you should update to the latest APC Tracker 4.3.1. We've updated our UPS Client for APC devices to support the current APC firmware versions. And as we actually touched a good and running system, we've also fixed some glitches in the interface to make APC Tracker as good looking as you knew it, again. And yes, we've found no problems running APC Tracker with Leopard, yet. You're already a registered APC Tracker user? Why waiting any longer to get your free update.