XE is not registering with the listener

Question

hi forum,
i installed oracle xe on an empty xp box. everything went smoothly but - like for so many others - my db homepage is not showing (http://127.0.0.1:8080/apex). but thats a different story.
i can connect with sqlplus, i can create, insert into and select from tables. tnsping is resolving localhost, xe, puss (my xp host name), 127.0.0.1 as well as the host ip (192.168.1.102).
my problem is that the db instance doesn't seem to register with the listener, so that when i do a sqlplus andy/passwd@XE i get the german version of what would be ORA-12514: TNS: Listener can't resolve service listed in connect discriptor
when i do a lsnrctl status i get the following:
LSNRCTL for 32-bit Windows: Version 10.2.0.1.0 - Production on 01-AUG-2010 11:53:26
Copyright (c) 1991, 2005, Oracle.  All rights reserved.
Anmeldung bei (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC_FOR_XE)))
STATUS des LISTENER
Alias                     LISTENER
Version                   TNSLSNR for 32-bit Windows: Version 10.2.0.1.0 - Produ
ction
Startdatum                31-JUL-2010 22:52:37
Uptime                    0 Tage 13 Std. 0 Min. 48 Sek.
Trace-Ebene               off
Sicherheit                ON: Local OS Authentication
SNMP                      OFF
Standard-Service           XE
Parameterdatei des Listener C:\oraclexe\app\oracle\product\10.2.0\server\network\admin\listener.ora
Log-Datei des Listener    C:\oraclexe\app\oracle\product\10.2.0\server\network\log\listener.log
Zusammenfassung Listening-Endpunkte...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(PIPENAME=\\.\pipe\EXTPROC_FOR_XEipc)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=puss)(PORT=1521)))
Services Übersicht...
Dienst "CLRExtProc" hat 1 Instance(s).
  Instance "CLRExtProc", Status UNKNOWN, hat 1 Handler für diesen Dienst...
Dienst "PLSExtProc" hat 1 Instance(s).
  Instance "PLSExtProc", Status UNKNOWN, hat 1 Handler für diesen Dienst...
Der Befehl wurde erfolgreich ausgeführt.the german msgs say that everything is in order basically, but what is certainly not in order is that there is no XE listed.
show parameter local_listener; revealed: no local listener set.
alter system set local_listener=XE; or
alter system set local_listener='(address=(protocol=tcp)(host=puss)(port=1521))'; and then
alter system register; didn't make the instance show in listener status
i would at least expect to see the attempt to register in the listener.log but nothing.
when i added the host to SID_LIST in listener.ora the instance was listed in the listener status, but status remained unknown, what ever i tried.
i know that there are other threads dealing with the same issue, but none of the solutions provided worked for me.
i am in a home network with two other macs connected via wlan. my firewall is turned off. i've tryed every combination of tnsnames.ora and listener.ora settings but nothing worked. after 13 hours of trail and error, reading a lot, wiping the whole box and reinstalling everything from scratch, sitting in front of my vanilla xp plus oracle xe installation, i'm tyred. i need your help.
Andy
tnsnames.ora
XE =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = puss)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = XE)
EXTPROC_CONNECTION_DATA =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC_FOR_XE))
    (CONNECT_DATA =
      (SID = PLSExtProc)
      (PRESENTATION = RO)
ORACLR_CONNECTION_DATA =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC_FOR_XE))
    (CONNECT_DATA =
      (SID = CLRExtProc)
      (PRESENTATION = RO)
listener.ora
SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = PLSExtProc)
      (ORACLE_HOME = C:\oraclexe\app\oracle\product\10.2.0\server)
      (PROGRAM = extproc)
    (SID_DESC =
      (SID_NAME = CLRExtProc)
      (ORACLE_HOME = C:\oraclexe\app\oracle\product\10.2.0\server)
      (PROGRAM = extproc)
LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC_FOR_XE))
      (ADDRESS = (PROTOCOL = TCP)(HOST = puss)(PORT = 1521))
DEFAULT_SERVICE_LISTENER = (XE)
sqlnet.ora
SQLNET.AUTHENTICATION_SERVICES = (NTS)

Answer 1

It turned out that the failing http://127.0.0.1:8080/apex actually was related.
After cutting the network connection and restarting the listener and the db everything worked fine, even the web admin interface.