My main desktop for the last couple of years has been a 24″ Apple iMac. While performance and reliability have been nothing less than bulletproof for the entire time I’ve had it, there is one really irritating problem that it’s suffered with for absolutely ages – and up until a few weeks ago went unsolved.
I use the machine every day, so I only ever send it to sleep rather than going through a full shut down. Unfortunately, it developed the very annoying habit of waking itself up in the middle of the night, sometimes for a couple of seconds only (spinning up the drives and fans, but not fully waking) but sometimes waking completely and staying that way.
1. Launch ‘System Preferences’
2. Load the ‘Energy Saver’ preference panel
3. Uncheck ‘Wake for network access’
Hopefully this will solve this annoying problem for you. My computer had been doing this for over 2 years now (possibly coinciding with my upgrade to Snow Leopard?) – since unchecking the network access box a couple of weeks ago it’s been behaving itself perfectly.