The last week or so my Leopard iMac has been waking up in the middle of the night… it’s quite annoying.
Finally found the answer here:
macrumors – leopard imac waking from sleep issue.
It turns out the problem is caused by having Screen Sharing enabled, and the 5900 port (VNC) being exposed to the outside world through my router. While this allows me to remote connect from another Mac ….
The problem lies in the fact that the screen comes to life whenever ANYTHING connects to this port, be it another Mac, or a port scanner… before even authentication takes place. Tested this by trying to SSH to that port – bang, my monitors come to life.
Fixed it by removing the external port forward, and just using SSH into the Mac. Apple needs to stop waking up the screens until authentication has taken place.
Basically this means that the really awesome TouchPad app that got Fireballed a few weeks ago is only really useful if you turn off your computer (completely) at night or are willing to manually turn off port 5900 (the VNC port).
The weird thing is that this worked fine on Tiger.
So perhaps with Snow Leopard this won’t be a problem… ?