the IP address is static, and it was...
However there is an update, after updating from server sw 10.6 to 10.6.2 and start over, restart the clients, etc., the server ran yesterday alll day, and the clients seem to stay online.
So it is almost running...
The library problem still remains, in the teamwork project missing objects everywhere, and the libraries marked 'Unavailable'
Interesting that in the Manage BIMServer libraries dialog the libraries seem to be available, moreover, the selected libraries could be Extracted without any problem.
Hacking the host file might be the way to go, I did it on my iMac, but didn't do that on the others (sudo nano etc/hosts ... and it reminded me that you got to have a non-empty used password with admin rights), so I will check that out, although it is weird that the server can be found via the fixed IP address, the server could only serve those libraries if the hostname is set in the hosts file....
The router DNS table is outside of my responsibility at this client, and every change in the router requires negotiaton and asking favor- I guess that should be common pattern for the BIMServer administrators.
I will post an update after hacking the etc/hosts file...