[Plugin: Post From Site] Categories don't attach

I’m having problem with the categories. When an anonymous user send a post it won’t attach the category to it, it will just attach the default category. It works great when the user is logged in but if it is a anonymous user the category they choose won’t attach to the post. Any ideas of what could be wrong

http://ww.wp.xz.cn/extend/plugins/post-from-site/