Built a hybrid, then operating it as core only. My system config has a couple other boxes going thru a trendnet kvm. I had the core up, then switched to my other main computer via the kvm. Sometime later, when I wanted to check the core (I'm working out how to setup my network with the core as dhcp svr) I got no response. Couldn't ping it, couldn't ssh into it. Now I don't have any MD's on the system, so the core really didn't have anything to do. I have also noticed that when the screensaver is on, I have to use an arrow button to 'wake it up' not the mouse. In fact, using either the mouse or 'shift ' key before an arrow key also does not get me out of the screensaver.
The biggest thing is having the core freeze up as it eventually will route web traffic to my other box. Any 'headless' experience out there? And I don't think it's the Mobo either, as I've had other *buntus on it w/o a freeze up.