"An Unidentified Error has occured" in defining MySQL database

Hello, I have a client that I am creating a site hosted with register.com. I have my IP address on their whitelist, and received the MySQL IP from the hosting company for the server info. I keep getting "an unidentified error has occured".

I was on support with them for awhile and they cant figure out why it isn't connecting. I also tried the following solution:
Host name = localhost (literally put localhost)
Database name = (cpanelUsername_databaseName)
Database username = (cpanelUsername_databaseUsername)
Database password = (whatever you picked)

that I got from the thread with the issues from hostgator.

Any thoughts? Any one else have issues connecting to register.com? It does have cPanel.

Thanks!