When I go through the shut down procedure on my 2007 iMac running snow leopard it goes to a blue screen and won't advance any further. I have to manually hold down the start button until it shuts down completely.
iMac, Mac OS X (10.6.8), Canon iR8070 copier
It's possible that Mac OS X is waiting for the close of an app in order to turn off the Mac. Try turning your Mac off with all apps closed, and see if it shuts down properly.
Additionally, hold Command and V keys while your Mac is starting to start up in verbose mode, so you will see the log instead of the blue screen during the shutdown. Doing this, we may identify what's causing the issue
iMac won't completely shut down
