Disqus Windows Phone SDK Launcher Not Work as Expected

[I Putu Yoga Permana]

Hi, i'm a windows phone app developer. I try your windows phone sdk recently. While this method work fine 

SDK.Instance.GetDiscussionDetailsAsync()

then i found that :

SDK.Launchers.LaunchDiscussionAsync()

only work using this parameter only: disqus ID or DsqDiscussion object. When using another parameter like disqusIdentifier or disqusUrl, It always said "Unable to retrieve data. Check your connection and try again". 

Any hint ? is this a bug or what ? Thanks in advance.