We think we've found the problem and fixed it on your site. There was a bug in our code on how we detect parent/child relationships in categories.
The way it's supposed to work (and should work on your site) is that if you setup an "Object" for a parent category, setup a channel for that parent category and then create content in any of the parent's children, that content will be autoposted as well.
On your site, you've created objects for many, many categories. That's ok if you need different settings for each, but you shouldn't need to if all you want to do is post from all of those categories.
That may all be confusing.. but what it comes down to is:
We created a "Κατηγορία (el-gr)" and a "Category (en-gb)" object on your site. You -could- setup your 2 channels for your Greek Facebook Page and your English Facebook Page to use the correct top-level object for the language. Then, whenever anything is posted in any of the subcategories of those objects, it will autopost to the correct language category.
We did not set it up this way in case there was some subcategory you didn't want to post. In that case, you may want to use a lower-level parent or may need to continue using objects for each sub-category... but you can probably simplify things a bit.
I apologize this took so long to figure out. It's a bug that's been around for quite some time, but it really only effected sites with large category structures like yours.
We'll be putting together a JFBConnect release over the next few weeks and this change will definitely be in it. It's already live on your site though.. so if you test and run into any further issues, please let us know!
Thanks,
-Melissa