Hello again, Marcel.
In our WordPress blog (cruzadavascaina.com.br) we are always experimenting a trouble: since we've setup our Add Link to Facebook to post on groups (some months ago, perhaps almost a year or more) - we try to create links for dozens of them, it was the reason to acquire the Pro version of this plugin - we get a kind of timeout error. It occurs almost one or two minutes after click on post button.
Obviously, trying to solve the trouble, we always do a refresh on the page to assure that our post go live. After this "workaround" (refresh on post page) the WordPress admin page finally succeds on show me the post (without errors) with the links apparently created on its sidebar.
What do you recomend to do to has a normal behavior (I mean, to post and add link to dozens of Facebook groups walls without timeout errors).