IntegrityError: duplicate key value violates unique constraint "venues_venue_longitude_2d904d039bce1526"

[Django] Error (EXTERNAL IP): /venues/add/

Traceback (most recent call last):

  File "/var/lib/python-support/python2.5/django/core/handlers/base.py", line 86, in get_response
    response = callback(request, *callback_args, **callback_kwargs)

  File "/var/lib/python-support/python2.5/django/contrib/auth/decorators.py", line 67, in __call__
    return self.view_func(request, *args, **kwargs)

  File "/srv/loco.ubuntu.com/loco_directory/venues/views.py", line 62, in venue_new
    form.save()

  File "/var/lib/python-support/python2.5/django/forms/models.py", line 319, in save
    return save_instance(self, self.instance, self._meta.fields, fail_message, commit)

  File "/var/lib/python-support/python2.5/django/forms/models.py", line 74, in save_instance
    instance.save()

  File "/var/lib/python-support/python2.5/django/db/models/base.py", line 311, in save
    self.save_base(force_insert=force_insert, force_update=force_update)

  File "/var/lib/python-support/python2.5/django/db/models/base.py", line 383, in save_base
    result = manager._insert(values, return_id=update_pk)

  File "/var/lib/python-support/python2.5/django/db/models/manager.py", line 138, in _insert
    return insert_query(self.model, values, **kwargs)

  File "/var/lib/python-support/python2.5/django/db/models/query.py", line 894, in insert_query
    return query.execute_sql(return_id)

  File "/var/lib/python-support/python2.5/django/db/models/sql/subqueries.py", line 309, in execute_sql
    cursor = super(InsertQuery, self).execute_sql(None)

  File "/var/lib/python-support/python2.5/django/db/models/sql/query.py", line 1734, in execute_sql
    cursor.execute(sql, params)

IntegrityError: duplicate key value violates unique constraint "venues_venue_longitude_2d904d039bce1526"

<ModPythonRequest
path:/venues/add/,
GET:<QueryDict: {}>,
POST:<QueryDict: {u'comment': [u'There is a Metra Station right across the street (easily walkable): http://metrarail.com/metra/en/home/maps_schedules/metra_system_map/md-n/station.DEERFIELD.html\r\n\r\nIt is also easily accessible from the highway (and plenty of free parking)'], u'city': [u'Deerfield'], u'name': [u'Barnes & Noble'], u'country': [u'231'], u'longitude': [u'-87.846765518188'], u'_popup': [u'1'], u'venue_url': [u'http://store-locator.barnesandnoble.com/store/2020'], u'address': [u'728 North Waukegan Road'], u'latitude': [u'42.16528020353']}>,