ORA-28267: Invalid NameSpace Value
Cause : Context NameSpace conflicts with reserved key words or a secure Namespace is not allowed for this type of Application Context.
Action - How to fix it : DBA Scripts :: www.high-oracle.com/scripts
Use a valid namespace.
Well, the reason for above error is that i have taken the above script from a 11g database and running it on 10g database. 11g has bring some changes in password management. Below code is executed on 11g and user created successfully, which is expected result.