diff --git a/include/libtorrent/peer_info.hpp b/include/libtorrent/peer_info.hpp
index 732dd0991..3ed1a132e 100644
--- a/include/libtorrent/peer_info.hpp
+++ b/include/libtorrent/peer_info.hpp
@@ -56,7 +56,7 @@ namespace libtorrent
 		// in the other end. In the case of a web seed, the server type and
 		// version will be a part of this string.
 		std::string client;
-		
+
 		// a bitfield, with one bit per piece in the torrent. Each bit tells you
 		// if the peer has that piece (if it's set to 1) or if the peer miss that
 		// piece (set to 0).
@@ -179,7 +179,7 @@ namespace libtorrent
 
 			// this connection is obfuscated with RC4
 			rc4_encrypted = 0x100000,
-			
+
 			// the handshake of this connection was obfuscated
 			// with a diffie-hellman exchange
 			plaintext_encrypted = 0x200000
@@ -210,7 +210,7 @@ namespace libtorrent
 
 			// The peer was added from the fast resume data.
 			resume_data = 0x10,
-			
+
 			// we received an incoming connection from this peer
 			incoming = 0x20
 		};
@@ -261,7 +261,7 @@ namespace libtorrent
 		// this is the number of requests we have sent to this peer that we
 		// haven't got a response for yet
 		int download_queue_length;
-		
+
 		// the number of block requests that have timed out, and are still in the
 		// download queue
 		int timed_out_requests;
@@ -301,7 +301,7 @@ namespace libtorrent
 		int downloading_block_index;
 		int downloading_progress;
 		int downloading_total;
-	
+
 		// the kind of connection this is. Used for the connection_type field.
 		enum connection_type_t
 		{
@@ -317,7 +317,7 @@ namespace libtorrent
 
 		// the kind of connection this peer uses. See connection_type_t.
 		int connection_type;
-		
+
 		// an estimate of the rate this peer is downloading at, in
 		// bytes per second.
 		int remote_dl_rate;
diff --git a/include/libtorrent/torrent_handle.hpp b/include/libtorrent/torrent_handle.hpp
index 351e56c9e..0b5cdb3c5 100644
--- a/include/libtorrent/torrent_handle.hpp
+++ b/include/libtorrent/torrent_handle.hpp
@@ -1096,20 +1096,20 @@ namespace libtorrent
 		// ``flags`` are the same flags that are passed along with the ``ut_pex`` extension.
 		//
 		// ==== ==========================================
-		// 0x01 peer supports encryption
+		// 0x01 peer supports encryption.
 		// 
 		// 0x02 peer is a seed
 		// 
-		// 0x04 supports uTP. This is only a positive flags
-		//      passing 0 doesn't mean the peer doesn't
-		//      support uTP
+		// 0x04 supports uTP. If this is not set, the peer will only be contacted
+		//      over TCP.
 		// 
 		// 0x08 supports holepunching protocol. If this
 		//      flag is received from a peer, it can be
 		//      used as a rendezvous point in case direct
 		//      connections to the peer fail
 		// ==== ==========================================
-		void connect_peer(tcp::endpoint const& adr, int source = 0, int flags = 0) const;
+		void connect_peer(tcp::endpoint const& adr, int source = 0
+			, int flags = 0x1 + 0x4 + 0x8) const;
 
 		// ``set_max_uploads()`` sets the maximum number of peers that's unchoked
 		// at the same time on this torrent. If you set this to -1, there will be
diff --git a/include/libtorrent/torrent_peer.hpp b/include/libtorrent/torrent_peer.hpp
index 5b530bf11..2955b3f51 100644
--- a/include/libtorrent/torrent_peer.hpp
+++ b/include/libtorrent/torrent_peer.hpp
@@ -62,6 +62,10 @@ namespace libtorrent
 
 		tcp::endpoint ip() const { return tcp::endpoint(address(), port); }
 
+#ifndef TORRENT_DISABLE_LOGGING
+		std::string to_string() const;
+#endif
+
 		// this is the accumulated amount of
 		// uploaded and downloaded data to this
 		// torrent_peer. It only accounts for what was
diff --git a/src/peer_list.cpp b/src/peer_list.cpp
index c4690353f..89dfc5ecd 100644
--- a/src/peer_list.cpp
+++ b/src/peer_list.cpp
@@ -897,7 +897,8 @@ namespace libtorrent
 	}
 
 	// this is an internal function
-	bool peer_list::insert_peer(torrent_peer* p, iterator iter, int flags, torrent_state* state)
+	bool peer_list::insert_peer(torrent_peer* p, iterator iter, int flags
+		, torrent_state* state)
 	{
 		TORRENT_ASSERT(is_single_thread());
 		TORRENT_ASSERT(p);
diff --git a/src/torrent.cpp b/src/torrent.cpp
index b12188148..5ce5d60f5 100644
--- a/src/torrent.cpp
+++ b/src/torrent.cpp
@@ -346,12 +346,6 @@ namespace libtorrent
 			m_resume_data.reset(new resume_data_t);
 			m_resume_data->buf = p.resume_data;
 		}
-
-		update_want_peers();
-		update_want_scrape();
-		update_want_tick();
-		update_state_list();
-
 	}
 
 	void torrent::inc_stats_counter(int c, int value)
@@ -710,8 +704,6 @@ namespace libtorrent
 	{
 		TORRENT_ASSERT(is_single_thread());
 
-		INVARIANT_CHECK;
-
 #ifndef TORRENT_DISABLE_LOGGING
 		debug_log("creating torrent: %s max-uploads: %d max-connections: %d "
 			"upload-limit: %d download-limit: %d flags: %s%s%s%s%s%s%s%s%s%s%s%s"
@@ -822,6 +814,11 @@ namespace libtorrent
 			}
 		}
 
+		update_want_peers();
+		update_want_scrape();
+		update_want_tick();
+		update_state_list();
+
 		if (!m_torrent_file->is_valid() && !m_url.empty())
 		{
 			// we need to download the .torrent file from m_url
@@ -838,6 +835,10 @@ namespace libtorrent
 			set_state(torrent_status::downloading_metadata);
 			start_announcing();
 		}
+
+#if TORRENT_USE_INVARIANT_CHECKS
+		check_invariant();
+#endif
 	}
 
 	void torrent::start_download_url()
@@ -7393,7 +7394,15 @@ namespace libtorrent
 				sm = m_ses.utp_socket_manager();
 
 			// don't make a TCP connection if it's disabled
-			if (sm == 0 && !settings().get_bool(settings_pack::enable_outgoing_tcp)) return false;
+			if (sm == 0 && !settings().get_bool(settings_pack::enable_outgoing_tcp))
+			{
+#ifndef TORRENT_DISABLE_LOGGING
+				debug_log("discarding peer \"%s\": TCP connections disabled "
+					"[ supports-utp: %d ]", peerinfo->to_string().c_str()
+					, peerinfo->supports_utp);
+#endif
+				return false;
+			}
 
 			void* userdata = 0;
 #ifdef TORRENT_USE_OPENSSL
@@ -7998,10 +8007,29 @@ namespace libtorrent
 			, !m_allow_peers && m_auto_managed && !m_abort);
 	}
 
+	char const* list_name(int idx)
+	{
+#define TORRENT_LIST_NAME(n) case aux::session_interface:: n: return #n;
+		switch (idx)
+		{
+			TORRENT_LIST_NAME(torrent_state_updates);
+			TORRENT_LIST_NAME(torrent_want_tick);
+			TORRENT_LIST_NAME(torrent_want_peers_download);
+			TORRENT_LIST_NAME(torrent_want_peers_finished);
+			TORRENT_LIST_NAME(torrent_want_scrape);
+			TORRENT_LIST_NAME(torrent_downloading_auto_managed);
+			TORRENT_LIST_NAME(torrent_seeding_auto_managed);
+			TORRENT_LIST_NAME(torrent_checking_auto_managed);
+			default: TORRENT_ASSERT_VAL(false, idx);
+		}
+#undef TORRENT_LIST_NAME
+	}
+
 	void torrent::update_list(int list, bool in)
 	{
 		link& l = m_links[list];
 		std::vector<torrent*>& v = m_ses.torrent_list(list);
+
 		if (in)
 		{
 			if (l.in_list()) return;
@@ -8012,6 +8040,10 @@ namespace libtorrent
 			if (!l.in_list()) return;
 			l.unlink(v, list);
 		}
+
+#ifndef TORRENT_DISABLE_LOGGING
+		debug_log("*** UPDATE LIST [ %s : %d ]", list_name(list), int(in));
+#endif
 	}
 
 	void torrent::disconnect_all(error_code const& ec, operation_t op)
@@ -10904,7 +10936,15 @@ namespace libtorrent
 		TORRENT_ASSERT(is_single_thread());
 
 #if !TORRENT_USE_IPV6
-		if (!adr.address().is_v4()) return NULL;
+		if (!adr.address().is_v4())
+		{
+#ifndef TORRENT_DISABLE_LOGGING
+			error_code ec;
+			debug_log("add_peer() %s unsupported address family"
+				, adr.address().to_string(ec).c_str());
+#endif
+			return NULL;
+		}
 #endif
 
 #ifndef TORRENT_DISABLE_DHT
@@ -10912,7 +10952,7 @@ namespace libtorrent
 		{
 			// try to send a DHT ping to this peer
 			// as well, to figure out if it supports
-			// DHT (uTorrent and BitComet doesn't
+			// DHT (uTorrent and BitComet don't
 			// advertise support)
 			udp::endpoint node(adr.address(), adr.port());
 			session().add_dht_node(node);
@@ -10971,6 +11011,13 @@ namespace libtorrent
 		torrent_state st = get_peer_list_state();
 		torrent_peer* p = m_peer_list->add_peer(adr, source, flags, &st);
 		peers_erased(st.erased);
+
+#ifndef TORRENT_DISABLE_LOGGING
+			error_code ec;
+			debug_log("add_peer() %s connect-candidates: %d"
+				, adr.address().to_string(ec).c_str(), m_peer_list->num_connect_candidates());
+#endif
+
 		if (p)
 		{
 			state_updated();
diff --git a/src/torrent_peer.cpp b/src/torrent_peer.cpp
index 7a96ade12..004a71bc9 100644
--- a/src/torrent_peer.cpp
+++ b/src/torrent_peer.cpp
@@ -184,6 +184,17 @@ namespace libtorrent
 		return peer_rank;
 	}
 
+#ifndef TORRENT_DISABLE_LOGGING
+	std::string torrent_peer::to_string() const
+	{
+#if TORRENT_USE_I2P
+		if (is_i2p_addr) return dest();
+#endif // TORRENT_USE_I2P
+		error_code ec;
+		return address().to_string(ec);
+	}
+#endif
+
 	boost::uint64_t torrent_peer::total_download() const
 	{
 		if (connection != 0)