diff --git a/actionpack/CHANGELOG b/actionpack/CHANGELOG
index 94c0a6bf95c16ae95db958ddf1e808065e84d9ed..96eb8ac77dc5c97241ed53b6314dd57c0734ffe6 100644
--- a/actionpack/CHANGELOG
+++ b/actionpack/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Underscore dasherized keys in formatted requests [Jamis Buck]
+
 * Add MimeResponds::Responder#any for managing multiple types with identical responses [Jamis Buck]
 
 * Make the xml_http_request testing method set the HTTP_ACCEPT header [Jamis Buck]
diff --git a/actionpack/lib/action_controller/cgi_ext/cgi_methods.rb b/actionpack/lib/action_controller/cgi_ext/cgi_methods.rb
index f092a41d47e70103cc997b72f0f091c63a62076b..cd70836c6edaf64d308063bcdfab3751ac420207 100755
--- a/actionpack/lib/action_controller/cgi_ext/cgi_methods.rb
+++ b/actionpack/lib/action_controller/cgi_ext/cgi_methods.rb
@@ -71,7 +71,7 @@ def self.parse_formatted_request_parameters(mime_type, raw_post_data)
           { node.node_name => node }
       end
       
-      params || {}
+      dasherize_keys(params || {})
     rescue Object => e
       { "exception" => "#{e.message} (#{e.class})", "backtrace" => e.backtrace, 
         "raw_post_data" => raw_post_data, "format" => mime_type }
@@ -79,6 +79,18 @@ def self.parse_formatted_request_parameters(mime_type, raw_post_data)
 
   private
 
+    def self.dasherize_keys(params)
+       case params.class.to_s
+       when "Hash"
+         params.inject({}) do |h,(k,v)|
+           h[k.tr("-", "_")] = dasherize_keys(v)
+           h
+         end
+       else
+         params
+       end
+    end
+
     # Splits the given key into several pieces. Example keys are 'name', 'person[name]',
     # 'person[name][first]', and 'people[]'. In each instance, an Array instance is returned.
     # 'person[name][first]' produces ['person', 'name', 'first']; 'people[]' produces ['people', '']
diff --git a/actionpack/lib/action_controller/mime_responds.rb b/actionpack/lib/action_controller/mime_responds.rb
index 04ec1e5dd84dd6f73232a1f1582c17d51be8d784..140209a225e3e19f599472653100b4d330c1ce05 100644
--- a/actionpack/lib/action_controller/mime_responds.rb
+++ b/actionpack/lib/action_controller/mime_responds.rb
@@ -36,7 +36,7 @@ def custom(mime_type, *args, &block)
           @responses[mime_type] = block
         else
           if argument = args.first
-            eval("__mime_responder_arg__ = " + (argument.is_a?(String) ? "'" + argument + "'" : argument), @block_binding)
+            eval("__mime_responder_arg__ = #{argument.is_a?(String) ? argument.inspect : argument}", @block_binding)
             @responses[mime_type] = eval(DEFAULT_BLOCKS[(mime_type.to_sym.to_s + "_arg").to_sym], @block_binding)
           else
             @responses[mime_type] = eval(DEFAULT_BLOCKS[mime_type.to_sym], @block_binding)
diff --git a/actionpack/test/controller/webservice_test.rb b/actionpack/test/controller/webservice_test.rb
index c99abeaa9e5031687e2aece63cc7aa93df073254..90691e9e9cddc65f3eec598510809c46d411e501 100644
--- a/actionpack/test/controller/webservice_test.rb
+++ b/actionpack/test/controller/webservice_test.rb
@@ -19,7 +19,20 @@ class TestController < ActionController::Base
     session :off
 
     def assign_parameters
-      render :text => (@params.keys - ['controller', 'action']).sort.join(", ")
+      if params[:full]
+        render :text => dump_params_keys
+      else
+        render :text => (params.keys - ['controller', 'action']).sort.join(", ")
+      end
+    end
+
+    def dump_params_keys(hash=params)
+      hash.keys.sort.inject("") do |s, k|
+        value = hash[k]
+        value = Hash === value ? "(#{dump_params_keys(value)})" : ""
+        s << ", " unless s.empty?
+        s << "#{k}#{value}"
+      end
     end
 
     def rescue_action(e) raise end
@@ -88,16 +101,28 @@ def test_deprecated_request_methods
     assert_equal true, @controller.request.yaml_post?
     assert_equal false, @controller.request.xml_post?    
   end
+
+  def test_dasherized_keys_as_xml
+    ActionController::Base.param_parsers[Mime::XML] = :xml_simple
+    process('POST', 'application/xml', "<first-key>\n<sub-key>...</sub-key>\n</first-key>", true)
+    assert_equal 'action, controller, first_key(sub_key), full', @controller.response.body
+  end
+
+  def test_dasherized_keys_as_yaml
+    ActionController::Base.param_parsers[Mime::YAML] = :yaml
+    process('POST', 'application/x-yaml', "---\nfirst-key:\n  sub-key: ...\n", true)
+    assert_equal 'action, controller, first_key(sub_key), full', @controller.response.body
+  end
   
   
   private  
   
-  def process(verb, content_type = 'application/x-www-form-urlencoded', data = '')
+  def process(verb, content_type = 'application/x-www-form-urlencoded', data = '', full=false)
     
     cgi = MockCGI.new({
       'REQUEST_METHOD' => verb,
       'CONTENT_TYPE'   => content_type,
-      'QUERY_STRING'   => "action=assign_parameters&controller=webservicetest/test",
+      'QUERY_STRING'   => "action=assign_parameters&controller=webservicetest/test#{"&full=1" if full}",
       "REQUEST_URI"    => "/",
       "HTTP_HOST"      => 'testdomain.com',
       "CONTENT_LENGTH" => data.size,