I am back to zenphoto and make a new installation of 1.4.4 beta.
I found that both the setup and admin overview warn me the display_errors is turn ON, but actually it is set by ini_set on purpose (beta?), maybe it should control in zenphoto.cfg
BTW, about the zenphoto.cfg, since I am using nginx, the htaccess is no effect. Though the setup have warned this, it is better to emphasize the zenphoto.cfg could be read on browser without proper setting.