After sleep becomes unresponsive
After having my mac pro in sleep mode for a few hours the machine will not came back (won't wake up). I see the light next to the power button and the light on on the cinema display but no matter what I do it won't wake up.
I've tried remoting into it from another machine to see if its monitor but neither VNC, nor Screen Sharing nor any other remote software can get in--it basically goes into a sleep of death.
The only way to bring it back is to do a hard reboot. Upon finishing start up I get the message that the machine wasn't properly shut down, do I want to open, etc.
Then it comes back and everything is fine.
If I put it to sleep or if it goes to sleep by itself it will usually come back with no problem as long as it hasn't been too long.
I've tried everything but just can't seem to figure it out.
At first I thought my Drobo Pro may be causing it (because I have a hard time getting the drobo to mount after this happens (unlness i power cycle it) but its happening even if the Drobo isn't plugged in...
Any ideas guys?
Mac Pro, OS X Mountain Lion (10.8.2), 14 GB RAM Dual Xeon Quad Core