[SOLVED] Problems when I try to save my Atahualpa options

Hello everyone... These last days I am having a problem when I try to save my atahualpa options... For example, if I want to change the footer of my blog I cannot do it and this message appears in my browser:
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Forbidden

You don't have permission to access /holonomia/wp-admin/themes.php on this server.
Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

Apache/1.3.41 Server at www.montanaspersonales.es Port 80
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I suppose that this is a problem with my server instead with the theme...
What do you think about this?
Thanks in advance

P.S. Great theme!