Redmine

hi, i'm doing a plugin and when i click in his tab, load the plugin right but, the background of the tab doesn't appear blank like the others tabs...
any idea?

there are only a controller called general

init.rb

@require 'redmine'

Redmine::Plugin.register :ficha_general do
name 'Ficha Técnica General'
author 'Viavansi'
description 'Ficha técnica general de proyectos'
version '1.0'

settings :partial => 'settings/ficha_general_settings'

project_module :ficha_tecnica_general do
    permission :ver_fichas, {:general => [:tipologiaIndex,:estadoIndex,:entornoIndex,:companiesIndex]}, :public =>true  
    permission :modificar_fichas, {:general => [:tipologiaEdit,:tipologiaCreate,:estadoEdit,:estadoCreate,:entornoEdit,:entornoCreate,:companiesEdit,:companiesCreate]}
  end
  menu :project_menu, :ficha, { :controller => 'general', :action => 'tipologiaIndex' }, :caption => :label_ficha_general, :param => :project_id

end@

thanks