This version works great on my Sawtooth G4/450 running 10.2.6. I have no complaints, except that I wish the tracking speed settings would be effective on the login screen. My dad just bought a new 15" 1GHz iMac, which came preconfigured with 10.2.7 (6R42). MouseWorks 2.3 seems to install successfully, but after restarting, choosing MouseWorks from the System Preferences pane results in a message saying the driver is not installed. I was unable to make it work. Several attempts resulted in the same behavior. -Jake