My iMac would not sleep . . . not after the amount of time set in prefs and not after choosing sleep. When I chose sleep it just went dark a few seconds and then woke up. After trying several things, I got it to work by removing Kensington Trackball and using mouse that came with it. But I want to use the trackball! I have the latest driver and software I got off the Kensington site. I there anything I can try to get the trackball to stop onterfering with sleep?? because now I just have leave the mac awake all the time or power it down. Any suggestions would be appreciated. Thank you.