Index: boost/serialization/export.hpp
===================================================================
--- boost/serialization/export.hpp	(revision 3118)
+++ boost/serialization/export.hpp	(working copy)
@@ -98,7 +98,7 @@
     // generates the statically-initialized objects whose constructors
     // register the information allowing serialization of T objects
     // through pointers to their base classes.
-    instantiate_ptr_serialization((T*)0, 0);
+    instantiate_ptr_serialization((T*)0, 0, adl_tag());
 }
 
 // On many platforms, naming a specialization of this template is
Index: boost/archive/detail/register_archive.hpp
===================================================================
--- boost/archive/detail/register_archive.hpp	(revision 3118)
+++ boost/archive/detail/register_archive.hpp	(working copy)
@@ -8,6 +8,14 @@
 
 namespace boost { namespace archive { namespace detail { 
 
+// This is for the sake of GCC 4.1 et. al, which doesn't seem to see
+// the instantiate_ptr_serialization overloads generated by
+// BOOST_SERIALIZATION_REGISTER_ARCHIVE if they lexically follow the
+// call *unless* they are in an associated namespace of one of the
+// arguments.  I am not 100% sure of what the standard says on this
+// point, and am investigating. - Dave A.
+struct adl_tag {};
+
 template <class Archive, class Serializable>
 struct ptr_serialization_support;
 
@@ -26,7 +34,7 @@
 // in overload resolution with the functions declared by
 // BOOST_SERIALIZATION_REGISTER_ARCHIVE, below.
 template <class Serializable>
-void instantiate_ptr_serialization(Serializable*, int) {}
+void instantiate_ptr_serialization(Serializable*, int, adl_tag) {}
 
 // The function declaration generated by this macro never actually
 // gets called, but its return type gets instantiated, and that's
@@ -38,7 +46,7 @@
                                                                         \
 template <class Serializable>                                           \
 typename _ptr_serialization_support<Archive, Serializable>::type        \
-instantiate_ptr_serialization( Serializable*, Archive* );               \
+instantiate_ptr_serialization( Serializable*, Archive*, adl_tag );      \
                                                                         \
 }}}