diff --git a/AUTHORS b/AUTHORS
index bc9777f5b6f..69209659de3 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -23,7 +23,7 @@ Jose Gaspar (helped modify example/external/nameclient.cpp example for windows)
 Claudio Castellini (useful bug reports, drivers, QUICKSTART documentation)
 Michael Bucko (sig::yarp::draw fixes, bug reports)
 Nelson Gon\c calves (testing and patch for SWIG, Java, Matlab on MINGW)
-Marco Barbosa (64-bit linux bug fix)
+Marco Barbosa (64-bit linux bug fix, report of event notification problem)
 Tomassino Ferrauto (patches to Bottle implementation; shmem bug tracking)
 Boris Duran (patches for SWIG for motor control classes)
 Mattia Castelnovi (a bunch of drivers)
diff --git a/ChangeLog b/ChangeLog
index 29d362d3fba..9b422448b6d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,15 @@
+2009-01-20  Paul Fitzpatrick  <paulfitz@alum.mit.edu>
+
+	* src/libYARP_OS/src/PortCoreOutputUnit.cpp: when a message fails
+	to be written because the carrier has dropped, then break the
+	connection.  (Occasional messaging problems in unreliable
+	protocols like udp/mcast should not lead to a dropped carrier.
+	This is a fix for the "Port disconnect event problem" reported by
+	Marco Barbosa on robotcub-hackers mailing list.
+
+	* src/libYARP_OS/include/yarp/os/impl/Protocol.h: propagate
+	failure of communication to deactivation of carrier.
+
 2009-01-08 Lorenzo Natale <nat@liralab.it>
 	* conf/FindGthread.cmake
 	* conf/YarpReqLib.cmake
diff --git a/src/libYARP_OS/include/yarp/os/impl/Protocol.h b/src/libYARP_OS/include/yarp/os/impl/Protocol.h
index 64ca753d539..307a86eab74 100644
--- a/src/libYARP_OS/include/yarp/os/impl/Protocol.h
+++ b/src/libYARP_OS/include/yarp/os/impl/Protocol.h
@@ -392,7 +392,7 @@ class yarp::os::impl::Protocol : public OutputProtocol, public InputProtocol {
 
     virtual bool isActive() {
         YARP_ASSERT(delegate!=NULL);
-        return delegate->isActive();
+        return delegate->isActive() && checkStreams();
     }
 
     virtual bool isTextMode() {
diff --git a/src/libYARP_OS/src/PortCoreOutputUnit.cpp b/src/libYARP_OS/src/PortCoreOutputUnit.cpp
index 2b8fc796cb7..e1a79f76ce8 100644
--- a/src/libYARP_OS/src/PortCoreOutputUnit.cpp
+++ b/src/libYARP_OS/src/PortCoreOutputUnit.cpp
@@ -288,7 +288,12 @@ void PortCoreOutputUnit::sendHelper() {
             }
         }
         if (!done) {
-            op->write(buf);
+            if (op->isActive()) {
+                op->write(buf);
+            } 
+            if (!op->isActive()) {
+                done = true;
+            }
         }
     }
     if (done) {