Oracle Database Discussions

hi all,

i just installed Oracle10.2.0.1 on my laptop, and i got a problem when switching user in sql*plus: i can login using 'sqlplus / as sysdba' or 'sqlplus user/pwd' or 'sqlplus /nolog + conn user/pwd' or 'sqlplus /nolog' + 'conn / as sysdba'ì, but every time i try to switch user (i.e. every time i do a connect while being already logged into the database) i receive the error
ORA-12638 Credential retrieval failed
So i need to exit from sqlplus and start it again (you can see an example og what's happening at the end of this post)

I installed Oracle 10.2.0 and i created a simple db using dbca (no patches applied yet).
My laptop (win xp sp2, all patched installed) already had installled Oracle 9.2 client and Oracle 10.2 client, but I always connect to the database using the "right" sqlplus.exe, i.e. running
c:\oracle\product\10.2.0\db_1\BIN\sqlplus.exe

the glogin.sql is almost empty (there are only a few COL commands),
login.sql does not exists.

sqlnet.ora contains
SQLNET.AUTHENTICATION_SERVICES= (NTS)
and if i change it to
SQLNET.AUTHENTICATION_SERVICES= (NONE)
everything works fine.

So my questions are:
- why both NTS authentication and password authentication only work once with sqlnet.authentication_services=(NTS) ?
- How can I fix these essors to use both NTS and password authentication, as i am used to do?

thanks!

andrea

---------------------------------------------------
login example

Microsoft Windows XP [Versione 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.

C:\Documents and Settings\amonti>set ORACLE_SID=ORCL

C:\Documents and Settings\amonti>sqlplus / as sysdba

SQL*Plus: Release 10.2.0.1.0 - Production on Mar Ott 2 10:29:28 2007

Copyright (c) 1982, 2005, Oracle. All rights reserved.


Connesso a:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options

SQL> conn system/manager
ERROR:
ORA-12638: Recupero credenziali non riuscito


Avvertenza: Connessione a ORACLE interrotta.
SQL> conn / as sysdba
ERROR:
ORA-12638: Recupero credenziali non riuscito


SQL> exit

C:\Documents and Settings\amonti>sqlplus /nolog

SQL*Plus: Release 10.2.0.1.0 - Production on Mar Ott 2 11:28:35 2007

Copyright (c) 1982, 2005, Oracle. All rights reserved.

SQL> conn system/manager
Connesso.
SQL> conn / as sysdba
ERROR:
ORA-12638: Recupero credenziali non riuscito


Avvertenza: Connessione a ORACLE interrotta.
SQL>