Running problems

[ephigenie]

of course it is. IspCP was developed with a server with fixed ip's in mind.
It makes no sense to run a professional hosting environment on a server which is occassionlly connected to the internet only.
However you can get around that by putting all services on an internal IP - i.e. 192.168.0.1 - or whatever your internal net is.
Then on your firewall or router you direct all traffic on port 80 to your internal ip.
To make the external dns working ... i don't have a good idea. Maybe you should just try it with dyndns domains - therefor you can update the domain names via the dyndns client.