Mac mini set to never sleep, but seems to be sleeping anyway (does not respond to network)
I'm going to assume you rebooted after saving those energy settings. I've had the same problem and only ever found a work-around: [caffein] (http://lightheadsw.com/caffeine/) will keep your computer from going to sleep (I believe later versions have the ability to let he monitor sleep while keeping the CPU itself active). This may be slightly more convenient in that you only need to click the menu bar icon to let it sleep rather than opening up energy settings all the time.