unable to create database users

[bizstreet]

My mysql service in Plesk developed bugs and I removed mysql (using the Change>Modify option in Plesk from Add/Remove Programs) and reinstalled it using the same option.

I reconfigured Server>Databases>MySQL with the new root password.

Then tried to restore the databases from the psa backup.
It restored the databases, but did not create the database users in mysql (the restore process created the user entries in the psa.mdb but not in mysql)

I found that Plesk is not creating the mysql database users even when I create a new database.

Any idea how I get Plesk to create the database users alongwith the databases?