All I want for Christmas ...

... is to settle these encoding issues 
once and for all.

Let's override the accessor methods, which 
seems to offer a simpler solution.

Now with tests (for whatever that helps)...

app/models/revision.rb

@@ -1,4 +1,8 @@
 class Revision < ActiveRecord::Base
   belongs_to :page
   composed_of :author, :mapping => [ %w(author name), %w(ip ip) ]
+
+  def content
+    read_attribute(:content).as_utf8
+  end
 end