facebook android SDK unable to determine type of open graph object : book

i am upgrading my android app to the latest facebook SDk version "v4" the sdk is offering a better programing model indeed

but when trying to share a story using ether the new shareApi or the ShareDialog i am getting this error in the callback

unable to determine type of open graph object : book

this is my code

private void shareStoryUsingDialog(Activity activity, STORY_TYPE type ,String title, Bitmap bitmap, String peerID, Uri imgURL) {


    ShareOpenGraphAction action ;
    ShareOpenGraphContent content = null;
    ShareOpenGraphObject obj ;

    final SharePhoto photo;
    if(bitmap == null && imgURL != null){
        photo = new SharePhoto.Builder()
        .setImageUrl(imgURL).build() ;
    }else{
        photo = new SharePhoto.Builder().setBitmap(bitmap).build();
    }

    switch (type) {
    case WIN:
        String objty = "og:type" ; 
        obj = new ShareOpenGraphObject.Builder()
        .putString(objty, "books.book")
        .putString("books:isbn", "0-553-57340-3")
        .putString("og:title", "book title")
        //.putPhotoArrayList("og:image", new ArrayList<SharePhoto>() {{add(photo);}})
        .build();

        action = new ShareOpenGraphAction.Builder()
        .setActionType("books.reads")
        .putObject("book", obj)
        .build();

        content = new ShareOpenGraphContent.Builder()
        .setPreviewPropertyName("book")
        .setAction(action)
        //.setPeopleIds(peers)
        .build();

        break;
    }

    if(content != null){
        ShareDialog shareDiag = new ShareDialog(activity);
        shareDiag.registerCallback(callbackManager, shareCallback);
        if(ShareDialog.canShow(content.getClass()))
            shareDiag.show(content);
        //ShareDialog.show(activity, content);
        //ShareApi.share(content, shareCallback);
    }
}