I learn that moving hosting is pretty painless. I tought it would be much harder. But it takes a while for the nameserver to change.
Another thing is to make sure that your database is exported out and then upload to the new ones. If the name and password is changed, you will need to look for a config file which will include the password and username of the mySQL database. Change it to the new ones.
If your new host have a different username. You need to change the script path too. Each script (I think most, including Wordpress) will have one of its path in mySQL, only phpbb forum doesn’t have one.
Just login to phpmyadmin, then search for your old username, you should get like
/home/oldusername/domain/something.com/blog/
If you change you username, it should be different now.
This should be the same for DirectAdmin hosting company but I don’t know about cpanel.