form_tag with action parameter explicitly inside hash does not work

I am using rails-4.0.1 and ruby 2.0.0-rc2.
Please see the screenshot of the exception.

<a href="http://oi42.tinypic.com/2gt90uh.jpg" target="_blank"><img src="http://i42.tinypic.com/2gt90uh.png" border="0" alt="Image and video hosting by TinyPic"></a>

The form_tag description is here:
http://api.rubyonrails.org/classes/ActionView/Helpers/FormTagHelper.html#method-i-form_tag