So, following this I suppose:
As you may know, I'm unfortunately not working with this any longer...
But I did take some time to take a look at this. I was surprised to see I still had access to your admin and noticed the blog entry you were talking about is a draft. So I did a quick test and noticed the error. There is something wrong and weird going on indeed. The thumbnail doesn't show and there is a console error which I won't be able to debug right now.
Just want to let you know I'll try again and see what I can do as quickly as possible, but it may take some time.