Slideshow plugin with align plugin

Hello,

I get an issue using "slideshow" plugin, when I put this one on "config.js" my "align" plugin doesn't work...

My code :

  config.extraPlugins = 'justify'; // doesn't work
  config.extraPlugins = 'slideshow'; // works

An other way :

  //config.extraPlugins = 'justify'; // doesn't work
  config.extraPlugins = 'slideshow'; // works

The last way :

config.extraPlugins = 'justify'; // works
//config.extraPlugins = 'slideshow'; // doesn't work