list buttons don't render in Ckeditor 4

I just installed 4 and if apply the list  button nothing is rendered, but the css text style is not true.

In the previous version circles was shown, the text style remain the same of the other text.

Reading the source, the correct <ui> and <li> tags seems to be correct.

I use drupal 7, ckeditor program in 'libraries' and ckeditor module in 'modules'

Can you tell me something?

Thanks a lot