diff --git a/ChangeLog b/ChangeLog
index 8593a2f36..7513f29da 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,4 @@
+	* fixed crasing bug when closing while checking a torrent
 	* fixed bug causing a crash with a torrent with piece length 0
 	* added an extension to the DHT network protocol to support the
 	  exchange of nodes with IPv6 addresses.
diff --git a/include/libtorrent/session.hpp b/include/libtorrent/session.hpp
index cbfa23b0c..27a0da2f8 100755
--- a/include/libtorrent/session.hpp
+++ b/include/libtorrent/session.hpp
@@ -163,6 +163,10 @@ namespace libtorrent
 			piece_checker_data* find_torrent(const sha1_hash& info_hash);
 			void remove_torrent(sha1_hash const& info_hash);
 
+#ifndef NDEBUG
+			void check_invariant() const;
+#endif
+
 			// when the files has been checked
 			// the torrent is added to the session
 			session_impl& m_ses;
diff --git a/src/session.cpp b/src/session.cpp
index b4f06e450..942947959 100755
--- a/src/session.cpp
+++ b/src/session.cpp
@@ -112,6 +112,8 @@ namespace libtorrent { namespace detail
 				{
 					boost::mutex::scoped_lock l(m_mutex);
 
+					INVARIANT_CHECK;
+
 					// if the job queue is empty and
 					// we shouldn't abort
 					// wait for a signal
@@ -160,7 +162,8 @@ namespace libtorrent { namespace detail
 				if (t)
 				{
 					std::string error_msg;
-					t->parse_resume_data(t->resume_data, t->torrent_ptr->torrent_file(), error_msg);
+					t->parse_resume_data(t->resume_data, t->torrent_ptr->torrent_file()
+						, error_msg);
 
 					if (!error_msg.empty() && m_ses.m_alerts.should_post(alert::warning))
 					{
@@ -185,6 +188,7 @@ namespace libtorrent { namespace detail
 						// lock the session to add the new torrent
 						session_impl::mutex_t::scoped_lock l(m_ses.m_mutex);
 						mutex::scoped_lock l2(m_mutex);
+						INVARIANT_CHECK;
 
 						assert(m_torrents.front() == t);
 
@@ -276,6 +280,9 @@ namespace libtorrent { namespace detail
 
 				{
 					mutex::scoped_lock l(m_mutex);
+
+					INVARIANT_CHECK;
+
 					processing->progress = progress;
 					if (processing->abort)
 					{
@@ -299,7 +306,9 @@ namespace libtorrent { namespace detail
 					// lock the session to add the new torrent
 					session_impl::mutex_t::scoped_lock l(m_ses.m_mutex);
 					mutex::scoped_lock l2(m_mutex);
-				
+
+					INVARIANT_CHECK;
+
 					assert(!m_processing.empty());
 					assert(m_processing.front() == processing);
 
@@ -388,6 +397,7 @@ namespace libtorrent { namespace detail
 
 	detail::piece_checker_data* checker_impl::find_torrent(sha1_hash const& info_hash)
 	{
+		INVARIANT_CHECK;
 		for (std::deque<boost::shared_ptr<piece_checker_data> >::iterator i
 			= m_torrents.begin(); i != m_torrents.end(); ++i)
 		{
@@ -405,6 +415,7 @@ namespace libtorrent { namespace detail
 
 	void checker_impl::remove_torrent(sha1_hash const& info_hash)
 	{
+		INVARIANT_CHECK;
 		for (std::deque<boost::shared_ptr<piece_checker_data> >::iterator i
 			= m_torrents.begin(); i != m_torrents.end(); ++i)
 		{
@@ -421,7 +432,7 @@ namespace libtorrent { namespace detail
 			if ((*i)->info_hash == info_hash)
 			{
 				assert((*i)->processing == false);
-				m_torrents.erase(i);
+				m_processing.erase(i);
 				return;
 			}
 		}
@@ -429,6 +440,24 @@ namespace libtorrent { namespace detail
 		assert(false);
 	}
 
+#ifndef NDEBUG
+	void checker_impl::check_invariant() const
+	{
+		for (std::deque<boost::shared_ptr<piece_checker_data> >::const_iterator i
+			= m_torrents.begin(); i != m_torrents.end(); ++i)
+		{
+			assert(*i);
+			assert((*i)->torrent_ptr);
+		}
+		for (std::deque<boost::shared_ptr<piece_checker_data> >::const_iterator i
+			= m_processing.begin(); i != m_processing.end(); ++i)
+		{
+			assert(*i);
+			assert((*i)->torrent_ptr);
+		}
+	}
+#endif
+
 	session_impl::session_impl(
 		std::pair<int, int> listen_port_range
 		, fingerprint const& cl_fprint
diff --git a/src/storage.cpp b/src/storage.cpp
index d7aacf2c3..4468e2535 100755
--- a/src/storage.cpp
+++ b/src/storage.cpp
@@ -1528,10 +1528,10 @@ namespace libtorrent
 		{
 
 			m_storage.read(
-					&m_piece_data[0]
-					, m_current_slot
-					, 0
-					, int(m_info.piece_size(m_current_slot)));
+				&m_piece_data[0]
+				, m_current_slot
+				, 0
+				, int(m_info.piece_size(m_current_slot)));
 
 			if (m_hash_to_piece.empty())
 			{
@@ -1542,11 +1542,11 @@ namespace libtorrent
 			}
 
 			int piece_index = identify_data(
-					m_piece_data
-					, m_current_slot
-					, pieces
-					, num_pieces
-					, m_hash_to_piece);
+				m_piece_data
+				, m_current_slot
+				, pieces
+				, num_pieces
+				, m_hash_to_piece);
 
 			assert(num_pieces == std::count(pieces.begin(), pieces.end(), true));
 			assert(piece_index == unassigned || piece_index >= 0);
diff --git a/src/torrent.cpp b/src/torrent.cpp
index 9ac984262..00ce4e24d 100755
--- a/src/torrent.cpp
+++ b/src/torrent.cpp
@@ -957,7 +957,7 @@ namespace libtorrent
 		req.downloaded = m_stat.total_payload_download();
 		req.uploaded = m_stat.total_payload_upload();
 		req.left = bytes_left();
-		if (req.left == -1) req.left = 1000;
+		if (req.left == -1) req.left = 16*1024;
 		req.event = m_event;
 
 		if (m_event != tracker_request::stopped)