Cannot discover My Book Live in Windows Server 2008 R2

I couldn’t find a solution for this problem in the forum.

Background: I’m trying to use MBL as backup storage for two servers in a small business network. There are strict rules and severe GPO restrictions applied with some processes disabled. I have some control on the GPO and can change the policies temporary.
I had used an alone-station laptop as DHCP server to set a network-allowed static IP on the MBL and I’ve connected it in the network. The MBL can be pinged from the server but cannot be discovered during the installation process. I’ve turned on the network discovery (I had to allow SSDP Discovery , UPnP Device Host and Function Discovery Resource Publication services to do it), but the device is still undiscoverable. Prior to do this the discovery process continued till I stop it, after the change it stops after some time. I also cannot find MBL using “Map network device…”

So, I suppose there are some other processes I have to enable in order to use the MBL. Could you tell me which windows processes are used in the MBL-discovery and for normal use of the device? Do you have some advises for me?