Oracle Database Discussions

[Oracle 10g 10.1.0.2] TNS:listener does not currently know of service requested in connect

hi,
My system is Windows XP.
Oracle 10g : 10.1.0.2.0

I can connect through sqlplus (and toad) with the following command:

sqlplus scott/tiger /

but I cannot connect with this: sqlplus scott/tiger@localhost:1521:cambridg

I am trying to connect to my database cambridg on my computer (named eclipse).
Where is the problem ? Can anyone help me here ?

This is my tnsnames.ora

# tnsnames.ora Network Configuration File: c:\oracle\product\10.1.0\Db_1\network\admin\tnsnames.ora
# Generated by Oracle configuration tools.

CAMBRIDG =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = ECLIPSE)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = cambridg)
)
)

EXTPROC_CONNECTION_DATA =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC))
)
(CONNECT_DATA =
(SID = PLSExtProc)
(PRESENTATION = RO)
)
)



And my listener.ora :

# listener.ora Network Configuration File: c:\oracle\product\10.1.0\Db_1\network\admin\listener.ora
# Generated by Oracle configuration tools.

SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME = c:\oracle\product\10.1.0\Db_1)
(PROGRAM = extproc)
)
)

LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC))
)
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = ECLIPSE)(PORT = 1521))
)
)
)

A tnsping works perfect :

C:\bob>tnsping cambridg

TNS Ping Utility for 32-bit Windows: Version 10.1.0.2.0 - Production on 30-JUIL.
-2005 14:46:11

Copyright (c) 1997, 2003, Oracle. All rights reserved.

Used parameter files:

Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = ECLIPSE)
(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = cambridg)))
OK (20 msec)

I get the following message:

C:\>sqlplus scott/tiger@localhost:1521:cambridg

SQL*Plus: Release 10.1.0.2.0 - Production on Sam. Juil. 30 15:10:58 2005

Copyright (c) 1982, 2004, Oracle. All rights reserved.

ERROR:
ORA-12514: TNS:listener does not currently know of service requested in connect
descriptor

Also, in the services running, I can see that the listener is started and running:
OracleOraDb10g_home1TNSListener

Maybe it has something to do with the other listener, that I cannot start:
OracleOraDb10g_home1TNSListenerSID_LIST_LISTENER

Any help would be much appreciated as I am currently stucked with that.

Thanks a lot