Why Can't T-SQL Access Oracle DB When VB6 Can?

Hi all,

SQL Server 2005 SP2
Windows XP Pro SP2
Oracle 10g Client 10.2
Oracle Data Access Components 10.2 VB6
Oracle Rdb 7.1 (not Oracle RDBMS).

I trying to access a remote Oracle Rdb database via a linked server in SQL Server 2005 management studio but having no luck. The remote database is accessed via an Oracle alias in TNSNAMES.ORA called my_oledb (see below) and I know it works ok becuase I'm able to access the remote database via VB6 (ADODB) using a very simple app whose connection string looks like this...



con.ConnectionString = "Provider=OraOLEDB.Oracle.1;User ID=someusername;

Password=topsecret;Data Source=my_oledb"



I got this example VB appication off the net but have to admit I'm not sure of the difference between

OraOLEDB.Oracle.1 & OraOLEDB.Oracle.



The alias in TNSNAMES looks like this...



my_oledb =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP) (Host = spike) (Port = 1527))
)
(CONNECT_DATA = (SERVICE_NAME = oci_oledb)
)
)



I can also TNSPING this alias without any probems.



My SQL server linked server is setup as follows.



exec sp_addlinkedserver
@server = 'MFP2',
@srvproduct='Oracle',
@provider = 'OraOLEDB.Oracle.1',
@datasrc = 'my_oledb'


exec sp_addlinkedsrvlogin
@rmtsrvname='MFP2',
@useself='false',
@locallogin='sa',
@rmtuser='******',
@rmtpassword='******'



Using both openquery and four part naming (?) I get the following errors


select job_title from mfp2...jobs

OLE DB provider "OraOLEDB.Oracle.1" for linked server "mfp2" returned message "ORA-01017: invalid username/password; logon denied".

Msg 7303, Level 16, State 1, Line 1

Cannot initialize the data source object of OLE DB provider "OraOLEDB.Oracle.1" for linked server "mfp2".



There are no schemas in the Oracle database so I've just used three dots between the linked server and the table name.

Again I know this syntax works becuase I have used it sucessfully with ODBC drivers.



select * from openquery(mfp2,'select * from jobs')

OLE DB provider "OraOLEDB.Oracle.1" for linked server "mfp2" returned message "ORA-01017: invalid username/password; logon denied".

Msg 7303, Level 16, State 1, Line 1

Cannot initialize the data source object of OLE DB provider "OraOLEDB.Oracle.1" for linked server "mfp2".



The passwrods are correct on the Oracle database as these are the ones used in the VB6 application.



Trying to expand the catalogue also causes management studio to hang.



Anyone spot the obvious mistake?



I did read on the net a while ago that registry entries might be rquired on the PC/server, is this still necessary?



Thanks in advance



Dave