Environment.MachineName does not return my clustered MSMQ network

In my clustered MSMQ group, I added a general service resource which is a
COM+ app run as a NT service. "Use Network Name for Computer Name" is ticked.
For a testing purpose, there is only one method with one line:
return Environment.MachineName.ToString();
However, it only returns the local node machine name, not the MSMQ virtual
network name.

Tried to create a separate service and app group for this COM+ service app
with its own ip and network name ("Use Network Name for Computer Name" is
ticked), still the same result. Environment.MachineName always returns local
machine name.

My env. is WIndows server 2008. Two hyper-v virtual nodes.

Does anyone know why? a hyper-v bug?