[OS X TeX] NatBib problem

[Luis Vitorio Cargnini]

Hi,
Please as I said befor I'm using classic thesis as my default class an  
formating for my thesis, also I'm using natbib for my references, but  
for reason its not seems to be working properly:

I forced these parameters:

\usepackage[authoryear,square,sort]{natbib}


this style:

\bibliographystyle{plainnat}

The problem is my references still appearing as numbers and not as  
author year as I need, anyone have any insight about why its not  
working for me, neither in a simple document class article natbib  
seems to be working, using \citep command to cite.

Thanks.
Vitorio
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