Displaying rails application's rdoc api in new window

Am trying to display rdocs for an application from the same
application.
Have a faqs controller with this method:

    def view_api
      rdocPath = "#{get_project_directory}/rdoc/index.html"
      send_file( rdocPath, :type => 'text/html', :disposition =>
'inline')
    end

Have a route:

    map.view_api '/view_api', :controller=>'faqs', :action=>'view_api'

And a link_to in the faqs/index.html.erb

    <%= link_to "Test Automation API", view_api_path, { :target =>
'_blank', :class=>"ws-income" } %>

Problem is that I get a message like the folloowing in each of the
panels in the rdoc display:

Routing Error:
No route matches "/fr_class_index.html" with {:method=>:get}

The full path to the file should be "C:/Documents and Settings/pneve/
waftt/private/wf/ccer/rdoc/fr_class_index.html"

Routing Error:
No route matches "/files/private/wf/ccer/lib/ccer_util_rb.html" with
{:method=>:get}

Here the path should be "C:/Documents and Settings/pneve/waftt/private/
wf/ccer/lib/ccer_util_rb.html"

The rdoc for the application is partly dynamic, hence the
#{get_project_directory} above.

Any suggestions for getting the panels to show the real stuff? If I
open the index.html directly with a browser all is well. Rails
appears to intercept and insist on some routing stuff...

Ruby 1.8.6 p111
Rails 2.3.5
pat