More info would be helpful for troubleshooting.

What pool are you trying to point it to?

Is the machine Cold when you start it up? the auto tune machines need to be somewhat warm during startup, if its in a cold room sitting off for a while when you go to turn it back on it may not boot up properly, has to do with opening the circuits on the boards I think.

Whats your network configuration like? dhcp, static addresses?

Are you sure you are not missing anything from the pool config tab? If you are not using the failover pool slots its best to wipe all of the info out of those lines. I suggest setting up accounts on other pools and putting them into the slots in case your main pool does go down.