Rails url_for not finding the route which appears in Rake Routes? -

i have following rake routes:

user    /users/:id(.:format)                                     {:action=>"show", :controller=>"users"}

but when do, email template:

<%= link_to(@comment.user.full_name, user_url(:only_path => false), :style => 'color:#5196e3;text-decoration:underline;') %>

i following error: "actionview::template::error (no route matches {:action=>"show", :controller=>"users"}):"

thoughts? thanks

if @ route needs :id parse. should supply user this:

user_url(@comment.user, :only_path => false)

shell