My MacPro won't shut all the way off. It won't wake my monitors when I start it up. [View all]

I have a 2008 MacPro dual quad core running two monitors.

When I do a shut down, the slave monitor goes black and the left/main monitor goes all the way to the gray screen and then stops. The rotating "gear" is moving in the middle of the screen, and that's it. It will not shut down further. I have to hold the "On" button to shut it down.

Upon restart, the left/main monitor will sometimes turn on, sometimes not. The right/slave monitor never does. I have to manually turn it on.

The shut down is the biggest issue. I have tried a few things, to no avail. The most recent was a system reset of some sort. No affect whatsoever.

Anyone have any ideas?