We just installed a ZoneDirector 1200 and everything was working great. After a few hours I went to check on it and the web page doesn't load and pings say it's unreachable. If I power it off and on again it comes back, but after a few hours I lose it again. The lights on the ZD don't look any different. I have tried different switches and different ports. I've also tried static IP and DHCP and I updated the firmware. Power cycling the switch port doesn't help either.