Can't edit meta tags in admin/content/nodewords/meta-tags/other

Hi,
I'm adding custom meta tags for some pages on my site. The adding is ok and the tags are showed correctly on the page.
But, when trying to edit the meta tags created, the meta tag part of the edit form comes with empty fields, even if I have information saved (i.e description and keywords fields).
Also, putting new values on these fields and saving don't work.
The module is a fresh instalation.
Is there something I forgot to configure or this is a bug?
Thank you.