diff --git a/include/osg/Object b/include/osg/Object
index fe76d3b1a..7d8620e70 100644
--- a/include/osg/Object
+++ b/include/osg/Object
@@ -203,8 +203,8 @@ class OSG_EXPORT Object : public Referenced
         const Referenced* getUserData() const;
 
         
-        /** Add user data object.*/
-        void addUserObject(Object* obj);
+        /** Add user data object. Returns the index position of object added. */
+        unsigned int addUserObject(Object* obj);
 
          /** Add element to list of user data objects.*/
         void setUserObject(unsigned int i, Object* obj);
@@ -213,10 +213,10 @@ class OSG_EXPORT Object : public Referenced
         void removeUserObject(unsigned int i);
 
         /** Get the index position of specified user data object.*/
-        unsigned int getUserObjectIndex(const osg::Object* obj) const;
+        unsigned int getUserObjectIndex(const osg::Object* obj, unsigned int startPos=0) const;
         
         /** Get the index position of first user data object that matches specified name.*/
-        unsigned int getUserObjectIndex(const std::string& name) const;
+        unsigned int getUserObjectIndex(const std::string& name, unsigned int startPos=0) const;
 
         /** Get user data object as specified index position. */
         Object* getUserObject(unsigned int i);
@@ -225,10 +225,10 @@ class OSG_EXPORT Object : public Referenced
         const Object* getUserObject(unsigned int i) const;
 
         /** Get first user data object with specified name. */
-        Object* getUserObject(const std::string& name);
+        Object* getUserObject(const std::string& name, unsigned int startPos=0);
 
         /** Get first const user data object with specified name. */
-        const Object* getUserObject(const std::string& name) const;
+        const Object* getUserObject(const std::string& name, unsigned int startPos=0) const;
 
         /** Get number of user objects assigned to this object.*/
         unsigned int getNumUserObjects() const;
diff --git a/src/osg/Object.cpp b/src/osg/Object.cpp
index e0f0c6850..124c20519 100644
--- a/src/osg/Object.cpp
+++ b/src/osg/Object.cpp
@@ -85,7 +85,10 @@ void Object::removeUserObject(unsigned int i)
 
 void Object::setUserObject(unsigned int i, Object* obj)
 {
-     if (_userDataContainer.valid() && i<_userDataContainer->_objectList.size())
+     // make sure the UserDataContainer exists
+     getOrCreateUserDataContainer();
+
+     if (i<_userDataContainer->_objectList.size())
      {
          _userDataContainer->_objectList[i] = obj;
      }
@@ -109,11 +112,11 @@ const Object* Object::getUserObject(unsigned int i) const
      return 0;
 }
 
-unsigned int Object::getUserObjectIndex(const osg::Object* obj) const
+unsigned int Object::getUserObjectIndex(const osg::Object* obj, unsigned int startPos) const
 {
      if (_userDataContainer.valid())
      {
-        for(unsigned int i = 0; i < _userDataContainer->_objectList.size(); ++i)
+        for(unsigned int i = startPos; i < _userDataContainer->_objectList.size(); ++i)
         {
             if (_userDataContainer->_objectList[i]==obj) return i;
         }
@@ -122,11 +125,11 @@ unsigned int Object::getUserObjectIndex(const osg::Object* obj) const
      return 0;
 }
 
-unsigned int Object::getUserObjectIndex(const std::string& name) const
+unsigned int Object::getUserObjectIndex(const std::string& name, unsigned int startPos) const
 {
      if (_userDataContainer.valid())
      {
-        for(unsigned int i = 0; i < _userDataContainer->_objectList.size(); ++i)
+        for(unsigned int i = startPos; i < _userDataContainer->_objectList.size(); ++i)
         {
             Object* obj = _userDataContainer->_objectList[i].get();
             if (obj && obj->getName()==name) return i;
@@ -136,11 +139,11 @@ unsigned int Object::getUserObjectIndex(const std::string& name) const
      return 0;
 }
 
-Object* Object::getUserObject(const std::string& name)
+Object* Object::getUserObject(const std::string& name, unsigned int startPos)
 {
      if (_userDataContainer.valid())
      {
-         unsigned int i = getUserObjectIndex(name);
+         unsigned int i = getUserObjectIndex(name, startPos);
          return (i<_userDataContainer->_objectList.size()) ? _userDataContainer->_objectList[i].get() : 0;
      }
      else
@@ -149,11 +152,11 @@ Object* Object::getUserObject(const std::string& name)
      }
 }
 
-const Object* Object::getUserObject(const std::string& name) const
+const Object* Object::getUserObject(const std::string& name, unsigned int startPos) const
 {
      if (_userDataContainer.valid())
      {
-         unsigned int i = getUserObjectIndex(name);
+         unsigned int i = getUserObjectIndex(name, startPos);
          return (i<_userDataContainer->_objectList.size()) ? _userDataContainer->_objectList[i].get() : 0;
      }
      else