Index: Rakefile
===================================================================
--- Rakefile	(revision 127)
+++ Rakefile	(working copy)
@@ -34,8 +34,8 @@
 CS_COMPILER           = ENV['mono'].nil? ? 'csc' : 'gmcs'
 EXCLUDED_EXTENSIONS   = ['.old', '.suo', '.vspscc', '.vssscc', '.user', '.log', '.pdb', '.cache', '.swp']
 EXCLUDED_DIRECTORIES  = ['.svn', 'obj', '.', '..']
-
 require 'context'
+MRI_BINARY				 = UserEnvironment::MRI + "/bin/ruby.exe"
 
 # Add some utility methods to Pathname to support filtered lists
 
@@ -325,7 +325,7 @@
   task :dual => [:testhappy] do
     IronRuby.source_context do
       rake_output_message "Ruby\n"
-      invoke_mspec(UserEnvironment.mri)
+      invoke_mspec(MRI_BINARY)
       rake_output_message "IronRuby\n"
       invoke_mspec(path_to_ir)
       exit
@@ -405,7 +405,7 @@
     reporter,tag  = extract_reporter(reporter)
 
     chdir(get_source_dir(:tests) +'util'){
-      cmd =  "#{UserEnvironment.mri} #{UserEnvironment.mspec}/bin/mspec #{tag || 'ci'} -t #{path_to_ruby.join(" ")} -B #{UserEnvironment.config} #{run_spec} #{reporter}"
+      cmd =  "#{MRI_BINARY} #{UserEnvironment.mspec}/bin/mspec #{tag || 'ci'} -t #{path_to_ruby.join(" ")} -B \"#{UserEnvironment.config}\" #{run_spec} #{reporter}"
       exec_net cmd
     }
   end
@@ -637,7 +637,7 @@
 task :ruby do
   begin
     old_verbose,$VERBOSE = $VERBOSE,nil
-    $ruby_imp = [UserEnvironment.mri]
+    $ruby_imp = RUBY_BINARY
     ARGV = [ARGV[0],*ARGV[2..-1]]
   ensure
     $VERBOSE = old_verbose