Facebook. Maximum number of requests allocated to your application

Question

I have a Facebook aplication on my site with multi friend selector which posts to selected friends. When I test it on local host all works fine, but when I upload it to live server on the last step of sending when I click post to my selected friends, there is a pop-up warning saying :

Sorry, you have run out of requests to sent with this application. Please try again tomorrow

But it was my first post on the live server... What options or something else should I change to avoid this warning?

Added from comments

<fb:serverfbml width= "740" height="407" > 
    <script type="text/fbml"> 
        <fb:request-form action="%%POSTCARD_ACTION_URL%%?at=send_postcard" method="POST" type="POSTCARD" content='Click the View button to see the Postcard sent to you. <fb:req-choice url="%%FACEBOOK_ACTION_URL%%?view=%%hash%%" label="View">' invite="false">
            <input type="hidden" name="mail_hash" id ="mail_hash" value="%%hash%%"> 
            <fb:multi-friend-selector style="width:80%;" showborder="false" actiontext="Select the friends you want send postcard." rows="3" bypass="cancel" email_invite="false" />
        </fb:request-form> 
    </script> 
</fb:serverfbml>

I am using a multi-friend-selector wraped into serverfbml