ActionMailer mail.return_path on test_return_path_with_create should return an array

santiago@debian:~/Documentos/WyeWorks/Proys/rails/actionmailer$ rake test
(in /home/santiago/Documentos/WyeWorks/Proys/rails/actionmailer) /home/santiago/Documentos/WyeWorks/Proys/rails/activesupport/lib/active_support/core_ext/time/conversions.rb:64: warning: method redefined; discarding old to_date /home/santiago/Documentos/WyeWorks/Proys/rails/activesupport/lib/active_support/core_ext/time/conversions.rb:81: warning: method redefined; discarding old to_datetime (eval):1: warning: method redefined; discarding old template /home/santiago/Documentos/WyeWorks/Proys/rails/activesupport/lib/active_support/core_ext/string/output_safety.rb:40: warning: discarding old concat /home/santiago/Documentos/WyeWorks/Proys/rails/activesupport/lib/active_support/core_ext/class/inheritable_attributes.rb:168: warning: instance variable @view_paths not initialized /home/santiago/Documentos/WyeWorks/Proys/rails/activesupport/lib/active_support/core_ext/class/inheritable_attributes.rb:168: warning: instance variable @default_url_options not initialized ./test/mail_service_test.rb:1079: warning: method redefined; discarding old test_return_path_with_create /home/santiago/Documentos/WyeWorks/Proys/rails/actionpack/lib/action_controller/metal.rb:48: warning: method redefined; discarding old content_type= /home/santiago/Documentos/WyeWorks/Proys/rails/actionpack/lib/action_controller/metal.rb:56: warning: method redefined; discarding old status= /home/santiago/Documentos/WyeWorks/Proys/rails/activesupport/lib/active_support/core_ext/class/inheritable_attributes.rb:168: warning: instance variable @view_paths not initialized /home/santiago/Documentos/WyeWorks/Proys/rails/activesupport/lib/active_support/core_ext/class/inheritable_attributes.rb:168: warning: instance variable @default_url_options not initialized ./test/url_test.rb:23: warning: method redefined; discarding old receive (eval):1: warning: method redefined; discarding old _layout ./test/subscriber_test.rb:29: warning: ambiguous first argument; put parentheses or even spaces ./test/subscriber_test.rb:31: warning: ambiguous first argument; put parentheses or even spaces ./test/subscriber_test.rb:39: warning: ambiguous first argument; put parentheses or even spaces ./test/subscriber_test.rb:41: warning: ambiguous first argument; put parentheses or even spaces Loaded suite /usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake/rake_test_loader
Started
.................................................F............................................................................................. Finished in 4.605566 seconds.

1) Failure: test_return_path_with_create(ActionMailerTest)

[./test/mail_service_test.rb:1081:in `test_return_path_with_create'
 /home/santiago/Documentos/WyeWorks/Proys/rails/vendor/gems/ruby/1.8/gems/mocha-0.9.8/lib/mocha/integration/test_unit/ruby_version_186_and_above.rb:19:in `__send__'
 /home/santiago/Documentos/WyeWorks/Proys/rails/vendor/gems/ruby/1.8/gems/mocha-0.9.8/lib/mocha/integration/test_unit/ruby_version_186_and_above.rb:19:in `run']:

"another@somewhere.test" expected but was
["another@somewhere.test"].

143 tests, 344 assertions, 1 failures, 0 errors
rake aborted!
Command failed with status (1): [/usr/bin/ruby1.8 -w -I"lib:test" "/usr/lib...]

(See full trace by running task with --trace)