Not output feedback form for comments

Hi,
I just upgraded to 5.0.6
When I want to insert a comment, does not load the form, as shown in the URL:

I use the skin simple_zen

Help please!

I speak spanish.

I went to your site and found that is using Mystique skin, and a fully functional comment form as well ( please see the attached file ).

Regards!

So, after much testing I changed mystique and everything went well.
Thank you very much Manuel.

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