Passwords being stored as sha1 and pbkdf2_sha256
Did you perhaps upgrade from Django 1.3 to Django 1.4 while retaining user data?  Django 1.4 introduced the newer, more secure hash for password storage, but should still be backwards-compatible with the old hashes as far as I am aware.
I have a django auth_user table, and for some reason, some of the passcodes are stores as sha1$... and others pbkdf2_sha256$.... I don't see any rhyme or reason to it -- what is the difference between these two and why would some be stored as one version, but others as another?