...this is not purely confined to Anthony's system - I've been having exactly the same problems with my MC200, which is also connected via mains ethernet to a BT HH. I am running the latest version (.355), have updated my Mac OS to the latest version, but on trying to download ControlMac I get the message:

'unable to find Sooloos system core' etc

I have tried unplugging/rebooting everything, turning firewalls off on both HH & Mac to no avail. I have not yet tried configuring a static IP and wondered how to do it?
I dont want to go back to snow leopard... any ideas?

Thanks in advance,
Henry