Facebook share image sometimes not load or sometime wrong image load

Hello,

We have facebook share image issue on our site http://www.workingfromanywhere.com.au/

Sometimes image is not loading when share or like and sometimes wrong image is showing. We have checked the og:image tag that there is correct url and also checked the blog url on https://developers.facebook.com/tools/debug/, there it showing the error "og:image was not defined, could not be downloaded or was not big enough. Please define a chosen image using the og:image metatag, and use an image that's at least 200x200px and is accessible from Facebook. Image 'http://www.workingfromanywhere.com.au/images/easyblog_images/682/2e1ax_yoo_avenue_module_Wharf-for-About-page.jpg' will be used instead."

We checked that our og:image is having 400*225 size still it is showing the error and wrong url.

For example you can see our blog post http://www.workingfromanywhere.com.au/working/wfa-tips/entry/simplifying-the-paper-trail

We have also attached some screen shots. Please review and advice.

Thanks.