First of all, you need to have your databases on the server set to allow remote connections. This is something only our support technicians can do, so you'll need to submit a support request to have this done.

Then you need to configure DreamWeaver properly:

The tricky part is the "Testing Server", which you set in the Site Definition for your domain.

Here are the settings you need there (you need to change MYDOMAIN.COM to your real domain name, FTPLOGIN to your FTP username, and enter your password):

Server Model: PHP MySQL
Access: FTP
FTP Host: MYDOMAIN.COM
Host Directory: httpdocs
Login: FTPLOGIN
Password: *****
Use Passive FTP: Checked
URL Prefix: http://www.MYDOMAIN.COM

(note that the URL Prefix is the tricky part, and it HAS to include the "http://"; AND the "www")

Then for the MySQL Connection. You reach this window from "Window >> Databases, and click on the "Databases" tab":

(Note that the Connection name can be anything, and substitute your domain for MYDOMAIN.COM, the database user you set up in your Server Administrator for DATABASEUSER, the password you assigned for that database user, and the name of the database you have set up in your Server Administrator for DATABASENAME

Connection name: WHATEVER
MySQL Server: MYDOMAIN.COM
User Name: DATABASEUSER
Password: *****
Database: DATABASENAME

You should be good to go!