I installed Snow Leopard Server on a new Mini. The install went fine. Shut the mini down. Started it up about 24 hours later, and I get to the gray screen and that's it. I exchanged the mini for a new one. Installed Snow Leopard Server on the new one. Install went fine. Ran updates. Restarted the mini several times with no problem. Shut it down, waited 24 hours, and now it's the gray screen again.