Parrallel south migration in django causes errors
Turns out the problem was that the git fetch on one of the front servers didnt take, which is what was causing the problem..it had nothing to do with running migrations in parallel (though I shouldnt have done that anyway)
I ran a code update that points at two front end servers (Amazon Web Service Instances).
A south migration was included as part of the update.Since the migration the live site appears to flit between the current code revision , and the previous revision, at will. 
Since discovering this, A previous developer (who has left the company before I turned up), said, & I quote:

"never run migrations in parallel. Running migrations twice causes duplication of new objects >and other errors!"

My code changes did not involve any models.py changes ; the migrate commands were just part of the fabric update script. Also no errors were thrown during the migrations, they seemingly ran as normal.
I have database backups, so I can roll back the database as a last resort.
Is there any other way to sort the issue without doing this?
Thanks for reading
edit: I should add, I pushed the same code to a staging server and it worked fine, so the issue isnt the code