I don't know why you used the upgrade script. Hope that did not hose things up but here it goes.
When creating a user account in cpanel.
bhwebco_ubb
Means the user name is ubb. The bhwebco_ is added to the user name you enter when you select create user.
If they changed your account then the prefix may have changed.
so go into cpanel/MYSQl Databases and look at what the username is called now XXX_ubb I guess now. You may want to redo the password while you are at it. Since you have showed everyone your old username and password.
Then edit the config.inc.php file. The top few lines will show the database user and password. enter the complete username with the new prefix and enter the password.
