Hi Richard,
So last night I published a post without using the scheduling feature (usually all our posts are scheduled) and it seemed to work without any problems. Here is the URL to the post: http://www.liberonetwork.com/how-i-keep-stress-at-bay and here is the URL to the Facebook post: https://www.facebook.com/liberonetwork/posts/620060298006451
This morning a scheduled post was published and it was fine, too! (ie the thumbnail image showed up on facebook and it wasn't a weird URL) however, you will notice if you hit the "like" button on the post, it doesn't show the thumbnail. I have not run it through the Facebook debugger yet like you requested. Here is the URL: http://www.liberonetwork.com/escaping-from-everyday-life and the URL to where it appeared on facebook: https://www.facebook.com/liberonetwork/posts/620314697981011
I have noticed that sometimes it will work with publishing scheduled posts on facebook and sometimes it will just post the URL with to weird " ?fb_source=pubv1" at the end and no thumbnail. However, it is a continual problem that the "like" button never works properly until the URL has been run through Facebook's debugger.
Thanks for taking the time to help! And I will let you know if tomorrow's post shows up on facebook without a thumbnail.