I'm just posting this because it's a good workaround for Lion users with old mice and if someone runs into the same issue I did, I hope they can find this with Google. No need for replies I upgraded to 10.7 a few days back and have been having all kinds of peripheral troubles. I used a(n ancient) Logitech MX500. Under SL I didn't use the Logitech software and just used SL to map the mouse's buttons to various Spaces/Expose functions. Unfortunately this wasn't really possible under Lion (especially moving back and forth between Desktops), so I set a hot key to do so (Apple + Left/Right) and after downloading the latest (3.51) Logitech Software, bound it to my forward and back thumb buttons. However, every time I restarted OSX the driver would forget (only) those two keys and revert back to the defaults. The mouse worked correctly with LCC un-installed and Steermouse as a driver, but I wasn't going to pay $20 for a mouse I've already paid for and am hoping to replace in the near future. So I called Logitech, got the run around from them and was told to try version 3.30 of the LCC software (available here). However, the 3.30 installer won't work under Lion. They basically told me my mouse was busted and to buy a new one. I had no intention of doing so (why should I replace this mouse - it itself replaced another faulty Logitech mouse) and it worked fine under SL. So I basically took a long shot and opened up the LCC 3.30 software, by using "Show Package Contents" on the LCC-installer app. From there \Contents\Resources\Logitech Control Center.mpkg let me install with out the version check. 3.30 isn't made for Lion but by assigning hotkeys to mouse buttons (you may need to go into the Mission Control preference pane, disassociate the action from at its current key [i.e., change Mission Control from F9 to left control] then assign that key to a button on the mouse, and then assign it back in the Mission Control pref pane) and using the Spaces/Expose action, it basically does everything it should under Lion. I'm upgrading to a Magic Trackpad when I upgrade this laptop, but for those of us stuck using old mice for a while, this is a good work around for Logitech's notoriously garbage software. Or, hopefully, Apple will make Mission Control as granular as Spaces/Expose was and I'll be able to reassign those mouse buttons to moving between Desktops.