tnsping error ora-12557

[SMTZ]

Hola, ¿alguien sabe a qué se debe el siguiente error?

C:\Documents and Settings\David>tnsping ECODOMES

TNS Ping Utility for 32-bit Windows: Version 10.2.0.1.0 - Production on 25-OCT-2
006 22:15:05

Copyright (c) 1997, 2005, Oracle.  All rights reserved.

Archivos de parßmetros utilizados:
C:\oracle\product\10.2.0\db_1\network\admin\sqlnet.ora


Adaptador TNSNAMES utilizado para resolver el alias
Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = noname)(
PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = ECODOMES)))
TNS-12557: TNS:no se puede cargar el adaptador de protocolo

Adjunto los ficheros listener.ora y tnsnames.ora:

- listener.ora:

# listener.ora Network Configuration File: C:\oracle\product\10.2.0\db_1\NETWORK\ADMIN\listener.ora
# Generated by Oracle configuration tools.

LISTENER_ECODOMES =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = noname)(PORT = 1521))
    )
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
    )
  )


SID_LIST_LISTENER_ECODOMES =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = ECODOMES)
      (ORACLE_HOME = C:\oracle\product\10.2.0\db_1)
      (PROGRAM = extproc)		
    )
  )

- tnsnames.ora:

ECODOMES =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = noname)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = ECODOMES)
    )
  )

EXTPROC_CONNECTION_DATA =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
    )
    (CONNECT_DATA =
      (SID = PLSExtProc)
      (PRESENTATION = RO)
    )
  )

En el init.ora.xxx, el "db_name" es "ECODOMES", por lo que entiendo que están bien configurados los dos ficheros anteriores, además, puedo acceder perfectamente a la base de datos mediante el Oracle Enterprise Manager.

Gracias por la ayuda.