So I found another bug with Xen and VM.
With Xen you can add/assign new IP's to any instance as virtual or real interfaces.
However VM Pro doesn't seem to understand real interfaces and it doesn't see them at all when you are trying to assign a private IP to support SSL sites.
As you know Xen doesn't just assign them it also brings the real/virtual interfaces up.
I tried to edit the domains config manually and set the iface option but still VM Pro doesn't see this either that the domain has a private IP.
I don't know what else to try here... maybe you can help ?