Logitech's driver software, the "Logitech Control Center" has, from at least July '07, consistently and frequently caused kernel panics in Mac OS X. http://forums.logitech.com/logitech/board/message?board.id=mackb&message.id=480 http://daysofourmacbooks.blogspot.com/2007/07/update-logitech-control-center-wichtig.html http://www.macosxhints.com/article.php?story=20071211110149837 http://daringfireball.net/2007/10/blue_in_the_face http://blog.macromates.com/2007/logitech-control-center/ Let me be clear: the LCC software is a LEMON. The only way to get logitech peripherals working properly in OS is to buy a third party driver. Don't make the same mistake I did, and plunk down $80 for a top of the line mouse and then have to waste time and money figuring out why your system is now broken. This is not the apple way. Edit: The latest posted driver is LCC 240 http://www.logitech.com/index.cfm/428/130&cl=us,en?osid=9&file= In my own case, LCC240 did nothing. For many, it actually got worse! LCC240 is not a fix. Edit: Most of the posters below me have chimed in supporting logitech. Astoundingly, none of them, except Silver-Fox, and maybe fanbrain, advocate installing the software that ships with the mouse. They say things like: Only two people in this whole thread actually find LCC to be usable. What they fail to mention is that, without LCC, you can't bind anything to your mouse except expose & dashboard functions. E.G., no browser-back and browser-forward buttons (LOL! Can you imagine?) If you have a special input, for instance, one of the scroll-to-flywheel mice like the MX revolution, or the gyro functions of the MX air, you don't get to use them, even if you are willing to shell out for a third party driver. Dems da facts. It seems that no one in this thread (at the time of my writing this edit) is disputing them. One last edit: By the way, I realized that I not only have the power to save somebody some money, but I can save somebody else some time. I've installed and configured USB Overdrive, ControllerMate, and SteerMate. For my money, SteerMouse is best. It has a more intuitive interface for application scoped bindings, it has a mode that makes it easy to identify which button on your mouse is "button #13", and it is still under active development. It has fine grain control over acceleration and tracking speed. Extra points for coming PRE CONFIGURED with sensible bindings in place (this is the Apple Way). And even MORE extra points for including a terminal command in the documentation that lets me get back logitech's proprietary flywheel action with my MX revolution. No offense to the developer who writes USB Overdrive "in his spare time", but his app is bush-league by comparison. ControllerMate is interesting, but it took me almost an hour to configure my mouse with a simple configuration that actually took no time at all to configure in SteerMouse (because SteerMouse came pre-configured exactly as I would have done it), and about 15 minutes to configure in USB OverDrive (where 13 of those minutes were devising creative ways to find out which button on my mouse is mapped to #6, #7, #8, #11, #13, etc. After the first three or so, it gets a little hazy, and UOD reported 21 buttons for me to search through). I think ControllerMate targets gamers who want sophisticated controller programming abilities without knowing how to code. SteerMouse is the application that SHOULD ship with a $99 mouse.