To fix this, you need to remove the Unmonitored Computer Object in SCOM that represents the server where you want to install Gateway.
To do that, you must set the parameter 'Create VM to SCOM Agent Relationship' to False in our Discovery rule "SV102" (Target is 'VM').
That will stop the 'dummy' Computer Object being recreated.
Then delete the unwanted Computer Object from SCOM - there is an article here that should help - http://www.techlog.org/archive/2008/07/ ... ts_in_oper
Once you have installed the Gateway you can turn the discovery parameter back to True, to maintain the relationships between VM and SCOM Agent(s).
Please note - in our next update, we have changed the method of discovering this relationship, so those Unmonitored Computer Objects will not be created. So this problem won't occur in the future.
Hope that fixes it - any problem please let us know!