--- a/src/core/model/object-ptr-container.cc	Fri May 11 16:42:40 2012 +0200
+++ b/src/core/model/object-ptr-container.cc	Mon May 14 18:15:22 2012 +0200
@@ -43,7 +43,13 @@
 Ptr<Object>
 ObjectPtrContainerValue::Get (uint32_t i) const
 {
-  return m_objects.find (i)->second;
+  Iterator it = m_objects.find (i); 
+  Ptr<Object> value = 0;
+  if ( it != m_objects.end () )
+  {
+    value = m_objects.find (i)->second;
+  }
+  return value;
 }
 
 Ptr<AttributeValue>

--- a/src/core/test/attribute-test-suite.cc	Fri May 11 16:42:40 2012 +0200
+++ b/src/core/test/attribute-test-suite.cc	Mon May 14 18:15:22 2012 +0200
@@ -780,7 +780,7 @@
   //
   // Get the Object pointer from the value.
   //
-  Ptr<Object> a = map.Get (0);
+  Ptr<Object> a = map.Get (1);
   NS_TEST_ASSERT_MSG_NE (a, 0, "Ptr<Object> from VectorValue \"TestMap1\" is zero");
 
   //