diff -urN toto/boost_1_32_0/boost/signals/connection.hpp boost_1_32_0/boost/signals/connection.hpp
--- toto/boost_1_32_0/boost/signals/connection.hpp	2004-09-30 22:07:33.000000000 -0400
+++ boost_1_32_0/boost/signals/connection.hpp	2005-02-10 10:34:33.205296640 -0500
@@ -53,6 +53,7 @@
         void* signal;
         void* signal_data;
         void (*signal_disconnect)(void*, void*);
+	bool blocked ;
 
         std::list<bound_object> bound_objects;
       };
@@ -69,6 +70,12 @@
       connection(const connection&);
       ~connection();
 
+      // Block he connection: if the connection is still active, there
+      // will be no notification
+      void block() ;
+      void unblock() ;
+      bool is_blocked() const ;
+
       // Disconnect the signal and slot, if they are connected
       void disconnect() const;
 
@@ -162,6 +169,18 @@
         }
       };
 
+      // Determines if the underlying connection is callable, ie if
+      // it is connected and not blocked 
+      struct is_callable {
+        typedef connection_slot_pair argument_type;
+        typedef bool result_type;
+
+        inline bool operator()(const argument_type& c) const
+        {
+	  return c.first.connected() && !c.first.is_blocked() ;
+        }
+      };
+
       // Autodisconnects the bound object when it is destroyed unless the
       // release method is invoked.
       class auto_disconnect_bound_object {
diff -urN toto/boost_1_32_0/boost/signals/detail/slot_call_iterator.hpp boost_1_32_0/boost/signals/detail/slot_call_iterator.hpp
--- toto/boost_1_32_0/boost/signals/detail/slot_call_iterator.hpp	2004-07-24 22:29:29.000000000 -0400
+++ boost_1_32_0/boost/signals/detail/slot_call_iterator.hpp	2005-02-10 09:59:10.638975768 -0500
@@ -58,7 +58,8 @@
         slot_call_iterator(Iterator iter_in, Iterator end_in, Function f)
           : iter(iter_in), end(end_in), f(f), cache()
         {
-          iter = std::find_if(iter, end, std::not1(is_disconnected()));
+          //iter = std::find_if(iter, end, std::not1(is_disconnected()));
+	  iter = std::find_if(iter, end, is_callable());
         }
 
         typename inherited::reference
@@ -73,15 +74,20 @@
 
         void increment()
         {
-          iter = std::find_if(++iter, end, std::not1(is_disconnected()));
+          //iter = std::find_if(++iter, end, std::not1(is_disconnected()));
+	  iter = std::find_if(++iter, end, is_callable());
           cache.reset();
         }
 
         bool equal(const slot_call_iterator& other) const
         {
-          iter = std::find_if(iter, end, std::not1(is_disconnected()));
+	  
+          //iter = std::find_if(iter, end, std::not1(is_disconnected()));
+	  //other.iter = std::find_if(other.iter, other.end,
+	  //                        std::not1(is_disconnected()));
+	  iter = std::find_if(iter, end, is_callable());
           other.iter = std::find_if(other.iter, other.end,
-                                    std::not1(is_disconnected()));
+                                    is_callable());
           return iter == other.iter;
         }