I’ve always had problems putting my Mac to sleep. Sometimes, especially if I have been playing iTunes, it wakes up again immediately. This can happen 2-3 times before it accepts it should go to sleep. I just spotted some advice on MacFixIt for people having this problem with the new aluminium keyboards – connect the keyboard to a USB hub, rather than directly to the Mac.
It works for the older white keyboard in my case – the Mac mini now goes to sleep immediately, -every time- more often.
Update (2007-09-12): After I posted this, the situation did improve, but I’ve since had occasional problems getting the mini to go to sleep. An improvement, but the problem is still present.
