Currently Being ModeratedFeb 27, 2013 8:34 AM (in response to Treehumper)
This seems to be an issue that effects a few users (me included) and started at some point in OS X 10.6 Snow Leopard. Seems to be connected with Bluetooth failing to wake from sleep properly. The only 'fix' I've found that is 100% reliable is: System Preferences>Energy Saver and set 'computer sleep' to 'never'.
That's what I've been doing for the last 18 months or so, until the release of OS X 10.8.2. I've only had the problem a couple of times since then, so it looks like it's getting better but not fully fixed.
In fact, I had the problem yesterday for the first time in ages - keyboard/mouse or trackpad wouldn't wake the Mac. As an experiment, I plugged my iPod touch into a USB port and the Mac woke immediately .
Currently Being ModeratedMar 6, 2013 2:05 PM (in response to Paul_31)
I've disabled the bluetooth and put sleep mode to never. Hope that at least works!