HALLO  I have tried tips of the Kensington Tech Support with MouseWorks 3.0b2 and OS X 10.4.5: no solution of the problem. With a friend I have started an "experiment": on a G4 powerbook: no problem (OS X 10.3.9); on an iMaCG5 (10.4.4): the trackball was not recognized by power on; on a 2K -System: no problem.

By starting by power on: the Bluetooth tools for the Apple seem to start first and the USB 1.1 are not recognized at this moment.

But what to do??  
(Version 3.0b2)

HALLO  I have installed Mousworks X 2.9 and the same problem occurs: B y power on the trackball (USB) is not recognized. I Have a G5 Dual processor (2.3 GHz) Mac, OS X is 10.4.4. The same problem exists for Mouseworks X 2.8 and OS X 10.4. . After unplugging and replugging the trackball is recognized, by rebooting ( no power off) the trackball is recognized. It seems to be a problem of 10.4.x. By starting with power on, the OS didn't recognize the USB device though the trackball is plugged in. The Kernel Debugger of 10.4.4 says, that the OS is not able to recognize a number for the USB device.

Has anyone a solution?  
(Version 2.9)