Oracle Database Discussions

Hi
I have ora9i DB 9.2.0.1.0 ON WINDOWS 2000
I want to take full backup , export and import using OMS.
Please check how i configure OMS

1- Configure OMS
- Create new repository

2- Create new repository option
- Custom

3- Select DB location
- In another Existing Database

4- Select Database for repository
Username = itsys
Password = pwd
Service = umaora:1521:umdb
Conncet as = sysdba

5- Repository Login Information
Username = OEM_UMAORA_UMDB
Password = pwd
confirm = pwd

6- Select Repository user tablespace
Default tablespace = OEM_REPOSITORY
Temporary tablespace = TEMP

7- Create Repository Summary
Create local Database= No
Repository Username = OEM_UMAORA_UMDB
In Database = umaora:1521:umdb
Create User = Yes
Default tablespace = OEM_REPOSITORY
Temporary tablespace = TEMP
Update OMS Config = Yes

"F I N I S H"
----
Then start-->program-->ora9i-->Enterprise Manager Console
Login To Oracle Management Server
Administrator = sysman
Password = oem_temp
Management Server = umaora.umarine.local

Prompt to change password
Administrator = sysman
Password = PWDNEW
Confirm = PWDNEW
...
...
Connected to OEM USING OMS

Now here either i m connect to system as sysdba or normal
IMPORT and EXPORT wizards are going but
when ever i select the backup
This Error message comes

Using preferred credential, the following error occurd:
ORA-01031:Insufficient privileges

PLEASE TELL ME WHERE I GO WRONG
I WILL BE EXTEMELY THANKFUL

Regards
Rana Adnan