I think there is a solution for this (*******) problem in TID 10091521.

My problem was this DHCP server in the production tree with activated option
85 [Preferred Server].
After applying this registry key to my workstations in zen test tree:

[HKLM\SOFTWARE\Novell\Workstation Manager\Identification]
DWORD:"Disable Preferred Connection"=0x00000001

i do see inventory data, user history and i can remote controll all my
workstations in the zen test tree.

At last i am happy again and maybe you too