I first posted this issue on the facebook-page-publish site (http://wordpress.org/support/topic/fail-to-publish-custom-post-type?replies=1), since this is the support url provided in the readme file, but I'm unsure about if that was a good idea. Please forget me for double posting. Here's the post:
First of all, congratulations on your great plugin! It just does what I needed in a very neat and clean manner, as opposite to most of the Facebook plugins I've tried out.
My problem is that I have most of my content defined using a custom post type called "portfolio items" which came along with the wordpress theme I'm using. While I have no problems to publish regular posts and pages on facebook, when I try to do the same with a portfolio item nothing happens. The user interface looks the same, in the sense that I can perfectly see the "Publish to facebook" checkbox nearby the Publish/Update button, but when I click it nothing happens (I've noticed for regular posts and pages the checkbox turns to "Publish again in facebook") and the content does not reach facebook.
Hope you can help me debug this issue, I've seen your code and it's clean so it should be easy to fix the problem if you give some advice.
Thanks a lot in advance.
PS: I'm using the latest version of the plugin (0.4.1) with WordPress 3.6 and WPML: