fragment cache erorr - view 2 times

I have rails 3.0.9 + nginx + memcached + dalli.

#production.rb
config.cache_store = :dalli_store, Memcache_servers, { :namespace =>
'koolinar', :expires_in => 1.day, :compress => true }

#app/view/test/test.html.erb
  <% cache do %>hello<% end %>

in browser i get
hello hello

Result is shown twice.

Hope you can help me