Problem with 11g listener

Hi Everyone,
When I upgraded sid2 from 10.2.0.4 to 11.2.0.2, I stopped the 10g listener and created an 11g listener with an alias LISTENER_USER. After editing listener.ora, here is the contents:
 LISTENER_USER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = host.domain)(PORT = p#))
    )
  )
=====below is added later====
  (SID_LIST =
    (SID_DESC =
      (GLOBAL_DBNAME = sid1)
      (ORACLE_HOME =10g_home)
      (SID_NAME = sid1)
    )
    (SID_DESC =
      (GLOBAL_DBNAME = sid2)
      (ORACLE_HOME =11g_home)
      (SID_NAME = sid2)
    )
  )
======end of later addition
#
# Installation Generated Net8 Configuration
# Version Date: Jun-17-97
# Filename: Listener.ora
#

SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (GLOBAL_DBNAME = sid1)
      (ORACLE_HOME = 10g_home)