diff --git a/app/metal/itex.rb b/app/metal/itex.rb
index b63c027a..63e300bb 100644
--- a/app/metal/itex.rb
+++ b/app/metal/itex.rb
@@ -13,30 +13,63 @@ class Itex
   end
   
   private
-  
+
+  # plugable XML parser; falls back to REXML
+  begin
+    require 'nokogiri'
+    def self.xmlparse(text)
+      Nokogiri::XML(text) { |config| config.options = Nokogiri::XML::ParseOptions::STRICT }
+    end
+  rescue LoadError
+    require 'rexml/document'
+    def self.xmlparse(text)
+      REXML::Document.new(text)
+    end
+  end
+
+  #error message to return
+  def self.error(str)
+    "<math xmlns='http://www.w3.org/1998/Math/MathML' display='inline'><merror><mtext>" +
+       str + "</mtext></merror></math>"
+  end
+
+  # itex2MML parser
+  begin
+    require 'itextomml'
+    def self.parse_itex(tex, filter)
+      Itex2MML::Parser.new.send(filter, tex).to_utf8
+    end
+  rescue LoadError
+    def self.parse_itex(tex, filter)
+      error("Please install the itex2MML Ruby bindings.")
+    end  
+  end
+
+  # the actual response
   def self.response(env)
-    @params = Rack::Request.new(env).params
-    tex = (@params['tex'] || '').purify
-    case @params['display']
+    params = Rack::Request.new(env).params
+    tex = (params['tex'] || '').purify.strip
+    case params['display']
       when 'block'
         filter = :block_filter
       else
          filter = :inline_filter
     end
     return "<math xmlns='http://www.w3.org/1998/Math/MathML' display='" +
-        filter.to_s[/(.*?)_filter/] + "'/>" if tex.strip == ''
-    estart = "<math xmlns='http://www.w3.org/1998/Math/MathML' display='inline'><merror><mtext>"
-    eend = "</mtext></merror></math>"
+        filter.to_s[/(.*?)_filter/] + "'/>" if tex == ''
     begin
-      require 'itextomml'
-      @itex2mml_parser ||=  Itex2MML::Parser.new
-      @itex2mml_parser.send(filter, tex).to_utf8
-    rescue LoadError
-      estart + "Please install the itex2MML Ruby bindings." + eend  
+      doc = parse_itex(tex, filter)
+      # make sure the result is well-formed, before sending it off
+      begin
+        xmlparse(doc)
+      rescue
+        return error("Ill-formed XML.")
+      end
+      return doc
     rescue Itex2MML::Error => e
-      estart + e.to_s + eend
+      error(e.to_s)
     rescue
-      estart + "Unknown Error" + eend
+      error("Unknown Error")
     end
   end
 end
diff --git a/app/views/layouts/error.html.erb b/app/views/layouts/error.html.erb
index cbdd1596..5c03dfce 100644
--- a/app/views/layouts/error.html.erb
+++ b/app/views/layouts/error.html.erb
@@ -31,7 +31,11 @@
   </h1>
 
 <div id="Error-Content">
-<%= h @content_for_layout %>
+<%= if :raw
+      @content_for_layout
+    else
+      h @content_for_layout
+    end %>
 
 </div> <!-- Error-Content -->
 
diff --git a/test/functional/wiki_controller_test.rb b/test/functional/wiki_controller_test.rb
index ebd1166d..c63d4019 100644
--- a/test/functional/wiki_controller_test.rb
+++ b/test/functional/wiki_controller_test.rb
@@ -765,6 +765,11 @@ class WikiControllerTest < ActionController::TestCase
       'author' => 'AuthorOfNewPage'
 
     assert_equal 403, r.response_code
+    resp = %{<p>Access denied. Your IP address, 127.0.0.2, was found on one or more DNSBL blocking } +
+           %{list(s).</p>\n<p>See <a href='http://www.spamcop.net/w3m?action=checkblock&amp;ip=127.0.0.2} +
+           %{'>here</a> for more information.</p>\n<p>See <a href='http://www.spamhaus.org/query/bl?ip=1} +
+           %{27.0.0.2'>here</a> for more information.</p>\n}
+    assert_match Regexp.new(Regexp.escape(resp)), r.body
   end
 
   def test_dnsbl_filter_allow_action
diff --git a/vendor/plugins/dnsbl_check/lib/dnsbl_check.rb b/vendor/plugins/dnsbl_check/lib/dnsbl_check.rb
index a3bd44d1..c1ab3b06 100644
--- a/vendor/plugins/dnsbl_check/lib/dnsbl_check.rb
+++ b/vendor/plugins/dnsbl_check/lib/dnsbl_check.rb
@@ -45,7 +45,7 @@ module DNSBL_Check
         addr = Resolv.getaddress("#{host}") rescue ''
         if addr[0,7]=="127.0.0"
           logger.info("#{request.remote_addr} found using DNSBL #{host}")
-          ban_help << " See <a href='#{DNSBLS[host]}#{request.remote_addr}'>here</a> for more information."
+          ban_help << "\n<p>See <a href='#{DNSBLS[dnsbl]}#{request.remote_addr}'>here</a> for more information.</p>"
           passed = false
         end
       end
@@ -58,8 +58,8 @@ module DNSBL_Check
       $dnsbl_passed.push request.remote_addr
       logger.warn("#{request.remote_addr} added to DNSBL passed cache")
     else
-      render( :text => "Access denied. Your IP address, #{request.remote_addr}, was found on one or more DNSBL" +
-                       " blocking list(s).#{ban_help}", :status => 403, :layout => 'error')
+      render( :text => "<p>Access denied. Your IP address, #{request.remote_addr}, was found on one or more DNSBL" +
+                       " blocking list(s).</p>#{ban_help}", :status => 403, :layout => 'error', :locals => {:raw => true})
       return false
     end
   end