[AUCTeX] natbib works only in numerical mode

[Piter_]

Hi all.
I try to generate bibliography using natbib. I use debian testing.
But for \citet{KBK+04} it generates "autor?[1]"
and for \citep{Yonetani1967} it generates [2]
even if I use \usepackage[authoryear]{natbib}

Thanks in advance.
Petro