soap error indicates a communication error with the core. Most commonly a network issue such as DNS or the service on the core not responding. That is where I would start.
I am able to access the server from that host. DNS resolves and I can smb to the server from the host.
I thought it was network related as well but that doesnt seem to be the case at first glance.
What version of LDMS are you using? If you open up the agent as well, what version does it show the Inventory scanner? This can be found by navigating to Library/Application Support/LANDesk/bin and opening the LANDesk Agent.app