As you can see, both of those pages get the following warning from Facebook:
The 'og:image' property should be explicitly provided, even if a value can be inferred from other tags.
And neither of those posts actually have an image associated with it. The solution, then, would be for you to include an image in your posts; depending on your theme, maybe even a Featured Image (Post Thumbnail). Try that, and let me know how it goes.
2 things. First, Facebook complains about meta tags being in the body and not the head. I looked at your source (even with your copy-protection plugin, it's possible to view the source, all it does is remove my ability to right-click on elemtns on your site, thus making debugging more difficult; I'd suggest removing that plugin). I didn't see any meta tags in the body, but I DID see a the following in the head
<div style="position:fixed; top:0px; left:0px; z-index:3000; height:100%; width:100%; background-color:#FFFFFF">
There should not be a div element outside of the noscript. You should remove this or fix it. This is likely what's confusing Facebook.
However, there is also this message from Facebook:
Provided og:image is not big enough. Please use an image that's at least 200x200 px. Image 'http://thecrewenews.co.uk/wp-content/uploads/Crewe-News-logo-with-banner1.jpg' will be used instead.
You need to supply larger images in your post of you want Facebook to use them. For example, the image in that post is 198 by 300px, just small enough for FB to not use it.
If you have any posts with images that should definitely have been grabbed by FB, try running them through the FB debugger to see if there any other issues with them.