Hello,
If your external LAN interface is set to DHCP (hardware address), and you change it to static, supply the static IP, NetMask, DG & DNS... Upon reboot the staticlly assigned address is the same as the last DHCP assigned address before the reboot.
You essentially have to go into Configure this Server a second time to re-set the Static IP.
Obviously two Reboots and Post-upgrades take Aaaages
Only mildly annoying, but definately a Bug