diff --git a/samples/main-packet.cc b/samples/main-packet.cc
index 777f95815..8eda7a475 100644
--- a/samples/main-packet.cc
+++ b/samples/main-packet.cc
@@ -7,8 +7,11 @@ using namespace ns3;
 
 /* A sample Header implementation
  */
-class MyHeader : public Header {
+class MyHeader : public Header 
+{
 public:
+  static const char *GetUid (void);
+
   MyHeader ();
   virtual ~MyHeader ();
 
@@ -24,6 +27,13 @@ private:
   uint16_t m_data;
 };
 
+const char *
+MyHeader::GetUid (void)
+{
+  // make sure the string is really unique.
+  return "MyHeader.test.nsnam.org";
+}
+
 MyHeader::MyHeader ()
 {}
 MyHeader::~MyHeader ()
diff --git a/src/common/packet-metadata.cc b/src/common/packet-metadata.cc
index c62b7d8f5..75117bd3c 100644
--- a/src/common/packet-metadata.cc
+++ b/src/common/packet-metadata.cc
@@ -977,7 +977,7 @@ PacketMetadata::DoPrint (const struct PacketMetadata::SmallItem *item,
                          Buffer data, uint32_t offset, const PacketPrinter &printer,
                          std::ostream &os) const
 {
-  uint32_t uid = item->typeUid & 0xfffffffe;
+  uint32_t uid = (item->typeUid & 0xfffffffe) >> 1;
   if (uid == 0)
     {
       // payload.
@@ -1112,6 +1112,7 @@ template <int N>
 class HistoryHeader : public Header
 {
 public:
+  static const char *GetUid (void);
   HistoryHeader ();
   bool IsOk (void) const;
 private:
@@ -1123,6 +1124,15 @@ private:
   bool m_ok;
 };
 
+template <int N>
+const char *
+HistoryHeader<N>::GetUid (void)
+{
+  std::ostringstream oss;
+  oss << N << "HistoryHeader.ns3";
+  return oss.str ().c_str ();
+}
+
 template <int N>
 HistoryHeader<N>::HistoryHeader ()
   : m_ok (false)
@@ -1181,6 +1191,7 @@ template <int N>
 class HistoryTrailer : public Trailer
 {
 public:
+  static const char *GetUid (void);
   HistoryTrailer ();
   bool IsOk (void) const;
 private:
@@ -1192,6 +1203,16 @@ private:
   bool m_ok;
 };
 
+template <int N>
+const char *
+HistoryTrailer<N>::GetUid (void)
+{
+  std::ostringstream oss;
+  oss << N << "HistoryTrailer.ns3";
+  return oss.str ().c_str ();
+}
+
+
 template <int N>
 HistoryTrailer<N>::HistoryTrailer ()
   : m_ok (false)
diff --git a/src/common/packet-metadata.h b/src/common/packet-metadata.h
index be102a4d3..919f35e42 100644
--- a/src/common/packet-metadata.h
+++ b/src/common/packet-metadata.h
@@ -254,26 +254,26 @@ template <typename T>
 void 
 PacketMetadata::AddHeader (T const &header, uint32_t size)
 {
-  DoAddHeader (PacketPrinter::GetHeaderUid<T> (), size);
+  DoAddHeader (PacketPrinter::GetHeaderUid<T> () << 1, size);
 }
 
 template <typename T>
 void 
 PacketMetadata::RemoveHeader (T const &header, uint32_t size)
 {
-  DoRemoveHeader (PacketPrinter::GetHeaderUid<T> (), size);
+  DoRemoveHeader (PacketPrinter::GetHeaderUid<T> () << 1, size);
 }
 template <typename T>
 void 
 PacketMetadata::AddTrailer (T const &trailer, uint32_t size)
 {
-  DoAddTrailer (PacketPrinter::GetTrailerUid<T> (), size);
+  DoAddTrailer (PacketPrinter::GetTrailerUid<T> () << 1, size);
 }
 template <typename T>
 void 
 PacketMetadata::RemoveTrailer (T const &trailer, uint32_t size)
 {
-  DoRemoveTrailer (PacketPrinter::GetTrailerUid<T> (), size);
+  DoRemoveTrailer (PacketPrinter::GetTrailerUid<T> () << 1, size);
 }
 
 
diff --git a/src/common/packet-printer.cc b/src/common/packet-printer.cc
index 9ccda7668..b5a807d52 100644
--- a/src/common/packet-printer.cc
+++ b/src/common/packet-printer.cc
@@ -91,17 +91,17 @@ PacketPrinter::PrintChunk (uint32_t chunkUid,
                            uint32_t size) const
 {
   RegisteredChunks *registeredChunks = PacketPrinter::GetRegisteredChunks ();
-  NS_ASSERT (chunkUid >= 1 && chunkUid/2 <= registeredChunks->size ());
+  NS_ASSERT (chunkUid >= 1 && chunkUid <= registeredChunks->size ());
   for (PrinterList::const_iterator i = m_printerList.begin (); i != m_printerList.end (); i++)
     {
       if (i->m_chunkUid == chunkUid)
         {
-          DoPrintCallback cb = (*registeredChunks)[chunkUid/2-1].printCallback;
+          DoPrintCallback cb = (*registeredChunks)[chunkUid-1].printCallback;
           cb (i->m_printer, start, os, packetUid, size);
           return;
         }
     }
-  DoGetNameCallback cb = (*registeredChunks)[chunkUid/2-1].getNameCallback;
+  DoGetNameCallback cb = (*registeredChunks)[chunkUid-1].getNameCallback;
   std::string name = cb ();
   struct PacketPrinter::FragmentInformation info;
   info.start = 0;
@@ -120,8 +120,8 @@ PacketPrinter::PrintChunkFragment (uint32_t chunkUid,
                                    uint32_t fragmentEnd) const
 {
   RegisteredChunks *registeredChunks = PacketPrinter::GetRegisteredChunks ();
-  NS_ASSERT (chunkUid >= 1 && chunkUid/2 <= registeredChunks->size ());
-  DoGetNameCallback cb = (*registeredChunks)[chunkUid/2-1].getNameCallback;
+  NS_ASSERT (chunkUid >= 1 && chunkUid <= registeredChunks->size ());
+  DoGetNameCallback cb = (*registeredChunks)[chunkUid-1].getNameCallback;
   std::string name = cb ();
   struct PacketPrinter::FragmentInformation info;
   info.start = fragmentStart;
@@ -217,16 +217,16 @@ bool
 PacketPrinter::IsTrailer (uint32_t uid)
 {
   RegisteredChunks *registeredChunks = PacketPrinter::GetRegisteredChunks ();
-  NS_ASSERT (uid >= 1 && uid/2 <= registeredChunks->size ());
-  bool isHeader = (*registeredChunks)[uid/2-1].isHeader;
+  NS_ASSERT (uid >= 1 && uid <= registeredChunks->size ());
+  bool isHeader = (*registeredChunks)[uid-1].isHeader;
   return !isHeader;
 }
 bool 
 PacketPrinter::IsHeader (uint32_t uid)
 {
   RegisteredChunks *registeredChunks = PacketPrinter::GetRegisteredChunks ();
-  NS_ASSERT (uid >= 1 && uid/2 <= registeredChunks->size ());
-  bool isHeader = (*registeredChunks)[uid/2-1].isHeader;
+  NS_ASSERT (uid >= 1 && uid <= registeredChunks->size ());
+  bool isHeader = (*registeredChunks)[uid-1].isHeader;
   return isHeader;
 }
 
diff --git a/src/common/packet-printer.h b/src/common/packet-printer.h
index cd340545d..c79be0a3b 100644
--- a/src/common/packet-printer.h
+++ b/src/common/packet-printer.h
@@ -140,6 +140,7 @@ private:
   {
     DoPrintCallback printCallback;
     DoGetNameCallback getNameCallback;
+    std::string uidString;
     bool isHeader;
   };
   typedef std::vector<struct PacketPrinter::Printer> PrinterList;
@@ -291,12 +292,22 @@ uint32_t
 PacketPrinter::AllocateUid (bool isHeader)
 {
   RegisteredChunks *chunks = PacketPrinter::GetRegisteredChunks ();
+  uint32_t j = 0;
+  for (RegisteredChunks::iterator i = chunks->begin (); i != chunks->end (); i++)
+    {
+      if (i->uidString == T::GetUid ())
+        {
+          return j;
+        }
+      j++;
+    }
   RegisteredChunk chunk;
   chunk.printCallback = &PacketPrinter::DoPrint<T>;
   chunk.getNameCallback = &PacketPrinter::DoGetName<T>;
   chunk.isHeader = isHeader;
+  chunk.uidString = T::GetUid ();
   chunks->push_back (chunk);
-  uint32_t uid = chunks->size () * 2;
+  uint32_t uid = chunks->size ();
   PacketPrinter::PeekDefault ()->DoAddPrinter (uid, 
                                                MakeCallback (&PacketPrinter::DoDefaultPrint<T>).GetImpl (),
                                                MakeCallback (&PacketPrinter::DoDefaultPrintFragment));