I realize this may be an issue with the site instead of the plugin, but this is what is happening:
I have a multi-site install running six blogs, and on five of these blogs I've enabled the Really simple Facebook Twitter share buttons using the exact same settings on each. It works properly on all the blogs but one. On this blog - http://mangablog.net - when someone presses the "like" button on a post, Facebook likes the homepage instead of the individual post. Using the Facebook debugger, I can see that the problem is that the og:url is the main page instead of the post, so it's redirecting traffic there instead. Trouble is, I don't know how to fix this, since the og:url is not something I ever set myself. It worked automatically with each of the other blogs (mangabookshelf.com, soliloquyinblue.com, mangabookshelf.suitablefortreatment.com, mangacritic.com) when I enabled the plugin, but this one has the og:url set to mangablog.net, even for individual posts.
Anyone know what's gone wrong, and/or how I can fix it?