One of the first things I did when I took my new iMac G5 out of the box was connect and install a new Kensington optical scroll mouse.

My only complaint about my new iMac was that it frequently froze up, or went into kernel panic, forcing a hard restart with the power button held down. USB ports also stopped working, causing the mouse to be unresponsive, also forcing hard restarts. This repeated abuse to my hard drive led to a series of file system corruptions and eventually caused the drive to fail.

After replacing the midplane assy, and replacing the hard drive (and reinstalling Panther), the problem remained. I finally uninstalled Kensington Mouseworks and installed USB Overdrive. My cursor lockups and kernel panics both disappeared.

I do NOT recommend Kensington Mouseworks driver until they specifically address this failure mode. The mice are fine examples of computer rodents, but the driver will kill your hard drive.