I have searched the web for a while now but could not find something similar. After installing the 10.7.2 on my Early 2009 iMach I noticed that Button 4 (left hand side button) on the wired Apple Mouse stopped working - at least when using it with either Mission Control or Expose. I used this button to switch between Desktops which allowed me to drag files from application to application using the primary mouse button at the same time. Post Update, I only got Expose or Mission Control working when assigning it to the Scroll Wheel Button, which makes it impossible to hit the primary button at the same time. Of course, I can always use the Mouse in combination with the F3 Mission Control button on the keyboard, but that's not the same. Not sure if this issue is linked to the Apple Mouse not being fully supported by 10.7.2 or something on my machine. I also tried to install SteerMouse and use SteerMouse's button assignment - but no success. Weirdly, Button 4 works fine when assigning the Dashboard.... Any help would be great. Cheers!