[AUCTeX] natbib and syntax hightlighting

[Makmiller Martins Pedroso]

Hi all, 

I'm currently using the natbib package to manage my
references. Usually the commands \citet and \citep are highlightled in my tex file.  
However, if I use a separate class file
to load the natbib package, the commands \citet and \citep are *not*
highlighted in my tex file any more. Do you have any suggestion of how
I can solve this problem?

(Parsing the buffer on load and save are both enabled in my init file. I'm using AUCTeX 11.86). 

Thanks!

mak