[Plugin: Facebook Social Widgets] Plugin erros

Hello,

First, I would like to thank you for creating this plugin and also to inform you of an error:

Notice: Undefined property: FacebookWidgets::$pluginDirectory in /MY_DOMAIN_PATH/wp-content/plugins/facebook-social-widgets/facebook-social-widgets.php on line 25

Hope it helps.

http://ww.wp.xz.cn/extend/plugins/facebook-social-widgets/