To be sure you are deleting south history and to use syncdb as if no south exists, you have to delete migrations in two places:
- In the database: remove tables created by south
- Migration files: remove folders used by south. They are like "app_name/migrations"
If you don't need any data in your database (because it is testing for example), instead of remove only south tables, y recommend to do a complete reset. The commando to do that is
python manage.py reset_db --router=default
Hope it helps!
Some extra help
Generally, when you use syncdb and south is in your INSTALLED_APPS you get a message saying that some apps won't be synced and that you have to use migrations. Try to do a syncdb and look at the apps that can't be synced. If there are some of them, remove the "migrations" folder inside that apps and make a syncdb again. The app should't appear again in the list that can't be synced.