Insufficient privs connecting as sysdba on local machine

I just cannot get to the bottom of this problem - hopefully someone will have solved it before.

I have the dba group added to my osuser (not as a primary group, but as a secondary one):

$/env/balaply1>groups balaply1

bala dba mqm mqu

The oracle executable has the correct permissions (I think):

$/env/balaply1>ls -al $ORACLE_HOME/bin/oracle
-rwsr-s--x 1 oracle dba 264359360 Jun 28 2007 /dboracle/ orabase/product/10.2.0.2/bin/oracle

However when I try and login as sysdba from the balaply1 user, I get an insufficient privileges error:

$/env/balaply1>export $ORACLE_SID=balaply1
$/env/balaply1>sqlplus /nolog

SQL*Plus: Release 10.2.0.2.0 - Production on Tue Mar 4 12:39:15 2008

Copyright (c) 1982, 2005, Oracle. All Rights Reserved.

SQL> connect / as sysdba
ERROR:
ORA-01031: insufficient privileges

Has anyone got any idea what is wrong here?

Thanks,

Stephen. Received on Tue Mar 04 2008 - 08:34:19 CST