Thought it was, still doesn't help me.
I have the error
Cannot initialize the data source object of OLE DB provider "OraOLEDB.Oracle" for linked server "ORACLESRV1".
OLE DB provider "OraOLEDB.Oracle" for linked server "ORACLESRV1" returned message "ORA-12541: TNS:no listener". (.Net SqlClient Data Provider)
I think there must be something else preventing me from making the connection.
As an aside I can connect fine to this Oracle instance using TOAD/ Oracle SQL Developer, so I know that I am not 'blocked' as such.