Webplayer and Facebook Canvas

Hi,

I have a game setup for webplayer and set for Facebook Canvas with a Share button, code as below:

 public void Share ()
     {
         if (!FB.IsLoggedIn) {
             loginForSharing = true;
             CallFBLogin ();
             Debug.Log ("not logged, logging");
         } else {
             FB.Feed (
                 link: "http://apps.facebook.com/" + FB.AppId + "/?challenge_brag=" + (FB.IsLoggedIn ? FB.UserId : "guest"),
                 linkName: "Jelly Splash",
                 linkCaption: "I scored " + LevelManager.Score + " points, Try to beat me!",
                 picture: "https://www.valsoft.co.uk/jewel.png"
             );
         }
     }

Works as expected in the editor but does nothing when testing from Facebook.

It is not a permission issue as it does not require any special permissions to share.

I also post scores and Invite friends, which uses FB.Request and that works fine as well.

Has anyone else seen this behaviour with FB.Feed.