I've managed to get it running ;-)
Server: jOpenray on Win2003 server
Since I no longer have SRSS available I needed to specify the server
address via DHCP.
This was the tricky part:
On a Windows (2000, 2003 EE) DHCP service
Using the GUI DHCP admin tool
* 1) Run the DHCP administration tool by clicking Start,
Administrative Tools, DHCP
* 2) Click the + next to the server you want to add the options
* 3) Click on the Server Options folder
* 4) Click the Action menu item, and then click Configure
* 5) Make sure the General tab is the one you are working on.
* 6) Scroll through the Available Options list
* 7) Click on the check box next to 049 X Windows System Display
* 8) Fill in the IP address field.
* 9) Click the Add button to add the IP address to the list.
* 10) Repeat steps 7 and 8 if you have a list of IP addresses
* 11) Click on the check box next to 066 Boot Server Host Name.
* 12) Fill in the String value field with a single IP address or a
* 13) Click the OK button to accept and apply both Options.
Et voila. Works.