Auto_link into _blank window

I cannot seem to auto_link into a _blank window. What am I doing
wrong?

  <%= auto_link( @restaurant.website, :href_options => {:target =>
'_blank'} ) %>

http://groups.google.com/group/rubyonrails-talk/browse_thread/thread/590b60b9523f29b5/8d39e0684170bf56?hl=en&lnk=gst&q=auto_link+_blank#8d39e0684170bf56