flexget upgrade error

gistfile1.txt

2012-05-20 16:10 ERROR    schema                        Failed to upgrade database for plugin series: (OperationalError) index ix_episode_releases_episode_id already exists u'CREATE INDEX ix_episode_releases_episode_id ON episode_releases (episode_id)' ()
Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/flexget/schema.py", line 94, in upgrade_wrapper
    new_ver = func(ver, session)
  File "/usr/local/lib/python2.7/dist-packages/flexget/plugins/filter/series.py", line 68, in upgrade
    Index('ix_episode_releases_episode_id', release_table.c.episode_id).create(bind=session.bind)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/schema.py", line 2253, in create
    bind._run_visitor(ddl.SchemaGenerator, self)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 2302, in _run_visitor
    conn._run_visitor(visitorcallable, element, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1972, in _run_visitor
    **kwargs).traverse_single(element)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/sql/visitors.py", line 106, in traverse_single
    return meth(obj, **kw)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/ddl.py", line 102, in visit_index
    self.connection.execute(schema.CreateIndex(index))
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1450, in execute
    params)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1541, in _execute_ddl
    compiled
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1697, in _execute_context
    context)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1690, in _execute_context
    context)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/default.py", line 331, in do_execute
    cursor.execute(statement, parameters)
OperationalError: (OperationalError) index ix_episode_releases_episode_id already exists u'CREATE INDEX ix_episode_releases_episode_id ON episode_releases (episode_id)' ()