I'm using a Logitech G5 2007 Edition mouse with my Mac. I've had it since Tiger, and everything has worked fine. I use the 4th button (the back arrow button) to show all windows in Exposé and I use the 5th button (the forward arrow button) to show the desktop in Exposé.
I've not been using any third party software to configure the mouse, just the Exposé preferences in System Preferences. I won't use that rubbish Logitech Control Centre.
I recently upgraded to Snow Leopard and the 5th button doesn't invoke the show desktop exposé command any more. The 4th button and 3rd buttons work as intended.
I tried reassigning the 5th button to show Dashboard, and that worked! Why? I have no idea.
Basically, after some testing, any mouse button assigned to show desktop doesn't show the desktop. But assigning any other button to any other Exposé command works...
Any help would be great, thanks guys.