Users' PhpMyAdmin - Wrong username/password

[protocol]

Today, mutiple (possibly) all users on a particular server cannot access phpMyAdmin from the control panel. The message is "Wrong username/password". I resolved this for a user by resetting the mysql password for the main username of that user via whm. This does not seem to have effected the the users created by the users (in the form username_user). I think this username and password is only used for phpmyadmin access. BTW phpmyadmin is fine for the root user from whm.

So my questions is any ideas why this would happen? and is there a easy way to sync the mysql passords to the same as the main users?

Thanks

 

[bullwinkle]

I don't know if this helps, but I get that whenever 2 certain files get changed (I can't figure out why they get changed, either). the files are the php.ini files, in /usr/local/cpanel/3rdparty/etc and lib. I have to change the default_hostname variable.