Can't delete object with ManytoMany Relationship

[Dobbes]

If you have an object with a manytomany relationship you can't delete it within the admin interface. As it spits out this error.

Traceback (most recent call last):

  File "/home/punteney/dobbes.com/django/core/handlers/modpython.py", line 214, in get_response
    return callback(request, **param_dict)

  File "/home/punteney/dobbes.com/django/views/admin/main.py", line 1057, in delete_stage
    obj.delete()

  File "/home/punteney/dobbes.com/django/core/meta.py", line 57, in _curried
    return args[0](*(args[1:]+moreargs), **dict(kwargs.items() + morekwargs.items()))

  File "/home/punteney/dobbes.com/django/core/meta.py", line 760, in method_delete
    cursor.execute("DELETE FROM %s WHERE %s=%%s" % (opts.db_table, opts.pk.name), [getattr(self, opts.pk.name)])

  File "/home/punteney/dobbes.com/django/core/db/base.py", line 10, in execute
    result = self.cursor.execute(sql, params)

IntegrityError: ERROR:  update or delete on "blog_entries" violates foreign key constraint "$1" on "blog_entries_categories"
DETAIL:  Key (id)=(2) is still referenced from table "blog_entries_categories".

DELETE FROM blog_entries WHERE id=2

This is from trying to delete a blog entry that is tied to the categories. The line in the Entry model is:

meta.ManyToManyField(Category, filter_interface=meta.HORIZONTAL),

I can't remove the category linking before I delete it as it is a required field so it comes back with an error message saying that the field is required.

Looks like this ticket #13 may touch on this as well, as one of it's bullet points.

[nichyoung]

This problem manifests in the core flatfiles interface - you can't delete a flatfile as it must contain a many to many reference to a site.