diff --git a/include/boost/serialization/extended_type_info.hpp b/include/boost/serialization/extended_type_info.hpp
index 5bd78a28..2bfdb871 100644
--- a/include/boost/serialization/extended_type_info.hpp
+++ b/include/boost/serialization/extended_type_info.hpp
@@ -38,18 +38,31 @@ class BOOST_SERIALIZATION_DECL(BOOST_PP_EMPTY()) extended_type_info :
 private:
     virtual bool
     less_than(const extended_type_info &rhs) const = 0;
+    int type_info_key_cmp(const extended_type_info & rhs) const;
+    
     // used to uniquely identify the type of class derived from this one
     // so that different derivations of this class can be simultaneously
     // included in implementation of sets and maps.
-    const char * type_info_key;
-    int type_info_key_cmp(const extended_type_info & rhs) const;
+    const char * m_type_info_key;
+    // flag to indicate wheter its been registered by type;
+    bool m_self_registered;
+    // flag to indicate wheter its been registered by type;
+    bool m_key_registered;
+    // flag indicating that no virtual function should be called here
+    // this is necessary since it seems that at least one compiler (borland
+    // and one version of gcc call less_than above when erasing even
+    // when given an iterator argument.
+    bool m_is_destructing;
 protected:
-    const char * key;
-    extended_type_info(const char * type_info_key_);
+    const char * m_key;
+    extended_type_info(const char * type_info_key);
     ~extended_type_info();
 public:
     void self_register();
     void key_register(const char *key);
+    bool is_destructing() const {
+        return m_is_destructing;
+    }
     bool operator<(const extended_type_info &rhs) const;
     bool operator==(const extended_type_info &rhs) const {
         return this == & rhs;
@@ -58,7 +71,7 @@ public:
         return this != & rhs;
     }
     const char * get_key() const {
-        return key;
+        return m_key;
     }
     static const extended_type_info * find(const char *key);
     static const extended_type_info * find(const extended_type_info * t);
diff --git a/include/boost/serialization/extended_type_info_no_rtti.hpp b/include/boost/serialization/extended_type_info_no_rtti.hpp
index fa8cb3e2..9166c82e 100644
--- a/include/boost/serialization/extended_type_info_no_rtti.hpp
+++ b/include/boost/serialization/extended_type_info_no_rtti.hpp
@@ -42,9 +42,9 @@ namespace detail {
 class BOOST_SERIALIZATION_DECL(BOOST_PP_EMPTY()) extended_type_info_no_rtti_0 : 
     public extended_type_info
 {
-protected:
     virtual bool
     less_than(const boost::serialization::extended_type_info &rhs) const ;
+protected:
     extended_type_info_no_rtti_0();
     ~extended_type_info_no_rtti_0();
 public:
@@ -59,11 +59,11 @@ template<class T>
 class extended_type_info_no_rtti_1 : 
     public extended_type_info_no_rtti_0
 {
-private:
-    // private constructor to inhibit any existence other than the 
-    // static one
+protected:
     extended_type_info_no_rtti_1(){}
 public:
+    // note borland complains at making this destructor protected
+    ~extended_type_info_no_rtti_1(){};
     static const boost::serialization::extended_type_info *
     get_derived_extended_type_info(const T & t){
         // find the type that corresponds to the most derived type.
@@ -93,7 +93,12 @@ public:
 template<class T>
 class extended_type_info_no_rtti : 
     public detail::extended_type_info_no_rtti_1<const T>
-{};
+{
+    // private constructor to inhibit any existence other than the 
+    // static one
+    extended_type_info_no_rtti(){}
+    ~extended_type_info_no_rtti(){};
+};
 
 } // namespace serialization
 } // namespace boost