diff --git a/app/models/chunks/chunk.rb b/app/models/chunks/chunk.rb
index 18c2d005..d6478a56 100644
--- a/app/models/chunks/chunk.rb
+++ b/app/models/chunks/chunk.rb
@@ -1,4 +1,3 @@
-require 'digest/md5'
 require 'uri/common'
 
 # A chunk is a pattern of text that can be protected
@@ -29,12 +28,12 @@ module Chunk
     # a regexp that matches all chunk_types masks
     def Abstract::mask_re(chunk_types)
       tmp = chunk_types.map{|klass| klass.mask_string}.join("|")
-      Regexp.new("chunk(\\d+)(#{tmp})chunk")
+      Regexp.new("chunk([0-9a-f]+n\\d+)(#{tmp})chunk")
     end
     
     attr_reader :text, :unmask_text, :unmask_mode
 
-	def initialize(match_data, content) 
+    def initialize(match_data, content) 
       @text = match_data[0] 
       @content = content
       @unmask_mode = :normal
@@ -52,9 +51,17 @@ module Chunk
       end
     end
 
+    # should contain only [a-z0-9]
     def mask
-      "chunk#{self.object_id}#{self.class.mask_string}chunk"
-	end
+      @mask ||="chunk#{@id}#{self.class.mask_string}chunk"
+    end
+
+    # We should not use object_id because object_id is not guarantied 
+    # to be unique when we restart the wiki (new object ids can equal old ones
+    # that were restored form madeleine storage)  
+    def id
+      @id ||= "#{@content.page_id}n#{@content.chunk_id}"
+    end
 
     def unmask
       @content.sub!(mask, @unmask_text)
diff --git a/app/models/page.rb b/app/models/page.rb
index 48adf729..105e3a1c 100644
--- a/app/models/page.rb
+++ b/app/models/page.rb
@@ -85,6 +85,11 @@ class Page
     @web.brackets_only ? name : WikiWords.separate(name)
   end
 
+  # used to build chunk ids. 
+  def id
+    @id ||= name.unpack('H*').first
+  end
+
   def link(options = {})
     @web.make_link(name, nil, options)
   end
diff --git a/app/models/revision.rb b/app/models/revision.rb
index d06c9a35..6277d326 100644
--- a/app/models/revision.rb
+++ b/app/models/revision.rb
@@ -88,11 +88,15 @@ class Revision
   end
 
   def clear_display_cache
-    @wiki_references_cache = @wiki_includes = @display_cache = nil
+    @wiki_references_cache = @published_cache = @display_cache = nil
+    @wiki_includes_cache = nil
   end
 
   def display_published
-    @published_cache = WikiContent.new(self, {:mode => :publish}) if @published_cache.nil?
+    unless @published_cache && @published_cache.respond_to?(:chunks_by_type)
+      @published_cache = WikiContent.new(self, {:mode => :publish})
+      @published_cache.render!
+    end
     @published_cache
   end
 
diff --git a/app/models/wiki_content.rb b/app/models/wiki_content.rb
index 5f46acf7..eaded5b7 100644
--- a/app/models/wiki_content.rb
+++ b/app/models/wiki_content.rb
@@ -39,10 +39,17 @@ require 'chunks/nowiki'
 # UPDATED: 22nd May 2004
 
 module ChunkManager
-  attr_reader :chunks_by_type, :chunks_by_id
+  attr_reader :chunks_by_type, :chunks_by_id, :chunks, :chunk_id
   
-  # regexp that match all chunk type masks
-  CHUNK_MASK_RE = Chunk::Abstract.mask_re(Chunk::Abstract::derivatives)
+  ACTIVE_CHUNKS = [ NoWiki, Category, WikiChunk::Link, URIChunk, LocalURIChunk, 
+                    WikiChunk::Word ] 
+
+  HIDE_CHUNKS = [ Literal::Pre, Literal::Tags ]
+
+  MASK_RE = { 
+    ACTIVE_CHUNKS => Chunk::Abstract.mask_re(ACTIVE_CHUNKS),
+    HIDE_CHUNKS => Chunk::Abstract.mask_re(HIDE_CHUNKS)
+  }
   
   def init_chunk_manager
     @chunks_by_type = Hash.new
@@ -50,33 +57,40 @@ module ChunkManager
       @chunks_by_type[chunk_type] = Array.new 
     }
     @chunks_by_id = Hash.new
+    @chunks = []
+    @chunk_id = 0
   end
 
   def add_chunk(c)
-    @chunks_by_type[c.class] << c
-    @chunks_by_id[c.object_id] = c
+      @chunks_by_type[c.class] << c
+      @chunks_by_id[c.id] = c
+      @chunks << c
+      @chunk_id += 1
   end
 
   def delete_chunk(c)
     @chunks_by_type[c.class].delete(c)
-    @chunks_by_id.delete(c.object_id)
-  end
-
-  def chunks
-    @chunks_by_id.values
+    @chunks_by_id.delete(c.id)
+    @chunks.delete(c)
   end
 
   def merge_chunks(other)
-    other.chunks_by_id.each_value{|c| add_chunk(c)}
+    other.chunks.each{|c| add_chunk(c)}
   end
 
   def scan_chunkid(text)
-    text.scan(CHUNK_MASK_RE){|a| yield a[0].to_i }
+    text.scan(MASK_RE[ACTIVE_CHUNKS]){|a| yield a[0] }
   end
   
   def find_chunks(chunk_type)
-    @chunks_by_id.values.select { |chunk| chunk.kind_of?(chunk_type) and chunk.rendered? }
+    @chunks.select { |chunk| chunk.kind_of?(chunk_type) and chunk.rendered? }
   end
+
+  # for testing and WikiContentStub; we need a page_id even if we have no page
+  def page_id
+    0
+  end
+
 end
 
 # A simplified version of WikiContent. Useful to avoid recursion problems in 
@@ -106,14 +120,7 @@ end
 
 class WikiContent < String
 
-  ACTIVE_CHUNKS = [ NoWiki, Category, WikiChunk::Link, URIChunk, LocalURIChunk, 
-                    WikiChunk::Word ] 
-  HIDE_CHUNKS = [ Literal::Pre, Literal::Tags ]
-
-  MASK_RE = { 
-    ACTIVE_CHUNKS => Chunk::Abstract.mask_re(ACTIVE_CHUNKS),
-    HIDE_CHUNKS => Chunk::Abstract.mask_re(HIDE_CHUNKS)
-  }
+  include ChunkManager
 
   DEFAULT_OPTS = {
     :active_chunks       => ACTIVE_CHUNKS,
@@ -124,8 +131,6 @@ class WikiContent < String
 
   attr_reader :web, :options, :revision, :not_rendered, :pre_rendered
 
-  include ChunkManager
-  
   # Create a new wiki content string from the given one.
   # The options are explained at the top of this file.
   def initialize(revision, options = {})
@@ -179,9 +184,9 @@ class WikiContent < String
   def render!
     pre_render!
     @options[:engine].apply_to(self)
-    # unmask in one go. $~[1].to_i is the chunk id
+    # unmask in one go. $~[1] is the chunk id
     gsub!(MASK_RE[ACTIVE_CHUNKS]){ 
-      if chunk = @chunks_by_id[$~[1].to_i]
+      if chunk = @chunks_by_id[$~[1]]
         chunk.unmask_text 
         # if we match a chunkmask that existed in the original content string
         # just keep it as it is
@@ -195,4 +200,8 @@ class WikiContent < String
     @revision.page.name
   end
 
+  def page_id
+    @revision.page.id
+  end
+
 end