My money is on a bug in the Apex in that it does not re-request a new DHCP lease when it expires. When this happens, any port-forwarding rules based upon the Apex NAME (not IP address) will no longer work.
For as many times as I post this no one either tells me I am right or wrong. It just keeps coming up.
I've seen all of my devices successfully re-request a DHCP lease except the Apex which goes stale.
SPotter, can you log into your router and look at the DHCP tables to see if the Apex is in there and its current status?
I have the same problem and I emailed Curt about it yesterday. When this happens to you again, email clp@neptunesys.com with your IP, user name, pass, and tell him what's wrong so he can look into it.
He told me to email him the next time it happens. What I did yesterday was reflash the firmware and update the web page. I'll see if it happens again in a couple of days. What happens to mine is that after a couple of days, it seems to lag so badly that it just doesn't connect anymore.