I don't know why you'd be getting that error if you dropped the tables from the default setup database, or if you just created a blank database and then run the backup into it.
If you set up the site using the install and then dropped the tables in the default database, then try setting up another blank database and then running your backup sql file into it. If it works then you'd have to edit both configure.php files with the name of the new database.
Vger



