2010 Mini refuses to shut down or load movie DVD after mountain lion upgrade

I upgraded my 2010 unibody mini w/ superdrive from 10.7x by using an update install from a usb drive. All seemed well until I realized that the mini will no longer shuts down (chosing shutdown menu leads to a reboot and the only way to totally shut down is to hold the power button down or pull the plug) and my superdrive no longer works with movie DVDs.

I've tried permission repair, zapping pram, disconnecting from power for 30 sec. then rebooting, and nothing is working still. Am I going to have to wipe the drive and try a clean install of mountain lion next?

Any ideas appreciated.