ORA-00401: the value for parameter compatible is not support

[sql] 
[oracle@rhel5 ~]$ sqlplus / as sysdba  
  
SQL*Plus: Release 10.2.0.1.0 - Production on Sun Aug 11 08:59:13 2013  
  
Copyright (c) 1982, 2005, Oracle.  All rights reserved.  
  
Connected to an idle instance.  
  
SQL> startup nomount;  
ORA-00401: the value for parameter compatible is not supported by this release