I could POST a question but it does not have a `question_id` and it does not show up in my account

Question

I could successfully create a question for my StackApp and I got this response (NSDictionary output):

{
    "has_more" = 0;
    items =     (
                {
            "creation_date" = 1393885003;
            "is_answered" = 0;
            "last_activity_date" = 1393885003;
            owner =             {
                "accept_rate" = 94;
                "display_name" = Besi;
                link = "http://stackoverflow.com/users/784318/besi";
                "profile_image" = "https://www.gravatar.com/avatar/df367a962f1cc17d3d8b3a1c304d5581?s=128&d=identicon&r=PG";
                reputation = 8090;
                "user_id" = 784318;
                "user_type" = registered;
            };
            score = 0;
            tags =             (
                "objective-c",
                osx,
                cocoa,
                nstextview
            );
            title = "How can I tab to and from an NSTextView";
        }
    );
    "quota_max" = 10000;
    "quota_remaining" = 9999;
}

The problem is now that I don't get a message_id in the response and the question does not show up in my account. What happened to this question?

Update: I just checked again and the problem is still there. I again got a JSON response like the one above, which seems to imply that my question has been created, but I don't find the question on my network.

These are my parameters that I send over to the API:

Answer 1

I figured out my error.

1. I did not have the client_id set.
2. I had to remove the preview flag.

I still can't create a question though: 400 when posting a question to the Stackexchange API