Correct Facebook Like/Post button on website to work properly - repost

We have a few pages with an addthis toolbar and og facebook tags. Some pages work correctly and others don't. When clicking the like button on some pages, it opens the window to post a comment, but clicking "Post" just makes the window blink and not post and close. 1. We would like you to identify what the problem is. 2. Give a working solution so that we can implement properly on the website.