From Tony Horrobin, "This fix just makes a couple of calls to ref_ptr<>::get() to satisfy the compiler.

The changes make the build successful under Windows 7/VC2005 and Ubuntu 9.10 with OSG_USE_REF_PTR_IMPLICIT_OUTPUT_CONVERSION set to OFF.
"

include/osgDB/Serializer

@@ -845,7 +845,7 @@ protected:
     serializer->add(#VALUE, MyClass::VALUE)
 
 #define END_ENUM_SERIALIZER() \
-    wrapper->addSerializer(serializer); }
+    wrapper->addSerializer(serializer.get()); }
 
 
 }