Ok let me try to explain:
there are two passwords associated with the admin@system-domain.
1) Master password: This is the password that you set while you first install SSO. This cannot be changed without using rsautil.cmd. If you forget what this is, you cannot even reset it via rsautil.
2) Admin password: This is the password you use to login to the web client. It is NOT necessary for this to be same as the master password. So if you logged in to web client and changed the password for admin@system-domain then this is the password that gets changed. The master password still remains the old one.
Also for the VC not appearing, you need to explicity provide the permissions in VC for admin@system-domain. By default admin doesnt have permissions to access VC.
Regards
Girish