libtorrent::torrent::check_invariant(): assertion failed

[arslanm]

version: 1.0.0.0
$Rev: 7680 $
file: 'libtorrent/src/torrent.cpp'
line: 6437
function: void libtorrent::torrent::check_invariant() const
expression: m_state != torrent_status::checking_files

stack:
1: assert_fail(char const*, int, char const*, char const*, char const*)
2: libtorrent::torrent::check_invariant() const
3: libtorrent::invariant_checker_impllibtorrent::torrent::invariant_checker_impl(libtorrent::torrent const&)
4: libtorrent::torrent::announce_with_tracker(libtorrent::tracker_request::event_t, boost::asio::ip::address const&)
5: libtorrent::torrent::stop_announcing()
6: libtorrent::torrent::do_pause()
7: libtorrent::aux::session_impl::pause()
8: void boost::asio::asio_handler_invoke<boost::_bi::bind_t<int, boost::_mfi::mf0<int, libtorrent::feed>, boost::_bi::list1<boost::_bi::value<boost::shared_ptrlibtorrent::feed > > > >(boost::_bi::bind_t<int, boost::_mfi::mf0<int, libtorrent::feed>, boost::_bi::list1<boost::_bi::value<boost::shared_ptrlibtorrent::feed > > >&, ...)
9: boost::asio::detail::completion_handler<boost::_bi::bind_t<void, boost::_mfi::mf0<void, libtorrent::aux::session_impl>, boost::_bi::list1<boost::_bi::valuelibtorrent::aux::session_impl* > > >::do_complete(boost::asio::detail::task_io_service*, boost::asio::detail::task_io_service_operation*, boost::system::error_code const&, unsigned long)
10: boost::asio::detail::task_io_service::do_run_one(boost::asio::detail::scoped_lockboost::asio::detail::posix_mutex&, boost::asio::detail::task_io_service_thread_info&, boost::system::error_code const&)
11: boost::asio::detail::task_io_service::run(boost::system::error_code&)
12: boost::asio::io_service::run(boost::system::error_code&)
13: libtorrent::aux::session_impl::main_thread()
14: boost::asio::detail::posix_thread::func<boost::_bi::bind_t<void, boost::_mfi::mf0<void, libtorrent::aux::session_impl>, boost::_bi::list1<boost::_bi::valuelibtorrent::aux::session_impl* > > >::run()
15: boost_asio_detail_posix_thread_function
16: _pthread_body
17: _pthread_body
18: thread_start