LDAP: null Update security configuration failed

[preetighongal]

Hello,
Iam trying to install Websphere Portal Server.
I have successfully installed
IBM HTTP Server
IBM Directory Server
IBM WebSphere Application Server.

Well in the Directory Server iam able to add the suffix and also the iam able to import the ldif file, where the users and groups are present.
In the Directory management tool iam able to see the users as well as the groups, but when i use the URL ldap://localhost:389
i get a Find people window when i say search for * it says there are no entries found in the directory.

Also when iam trying to enable security in Websphere Application, using the Security Console, i get the error :

Update security configuration failed

Exception:
LDAP:null
com.ibm.ejs.sm.exception.InvalidUserRegistryConfigException: LDAP:null


--------
com.ibm.ejs.sm.client.command.ExecutionException: Update security configuration failed

at com.ibm.ejs.sm.client.command.ModifySecurityConfigAttributesCommand.execute(ModifySecurityConfigAttributesCommand.java:70)

at com.ibm.ejs.sm.client.command.CommandManager$ExecutionThread.run(CommandManager.java:264)

at com.ibm.ejs.sm.client.command.ThreadPool$PooledThread.run(ThreadPool.java:89)

Please help me