Hi, I have the Magic Trackpad for a long time and I am using it with my mac mini without any problem, I also have a iMac(2.8GHz, 2GB RAM, Mac OS Lion installed) I tried to pair many times my iMac with the trackpad but it failed all of the times, even via bluetooth preferences or the trackpad preferences, I tried also to remove the batteries or to turn off and on again without any success, any help please!!