It is working correctly in the way you set it up. You added the form inside of an iframe. That puts the form inside of 2 iframe's now. Here is what you have:
<p><iframe id="fb_iframe" style="border: none; background: transparent; overflow: hidden; width: 100%;" src="http://www.mainemusicmakers.com/MMMBookingForm1/MMMBookingForm1.html" width="300" height="1287"></iframe></p>
</div>
That is not the markup we provide you. The correct markup we provide looks similar to this:
<script type="text/javascript">document.write(unescape("%3Ciframe id=\"fb_iframe\" src=\"cform.php" + window.location.search + "\" width=\"100%\" height=\"412\"allowtransparency=\"true\" scrolling=\"no\" frameborder=\"0\"%3E<a href=\"cform.php\" title=\"cform\">Check out my CoffeeCup Form</a>%3C/iframe%3E"));</script>
<noscript>
<iframe height="412" style="border:none; background:transparent; overflow:hidden; width:100%;"
id="fb_iframe" src="cform/cform.html">
<a href="cform.php" title="cform">Check out my CoffeeCup Form</a>
</iframe>
</noscript>
That is what you should be adding to your page at
http://mainemusicmakers.com/booking-info/
I would start by deleting that markup you added, export your form again and use the markup that the software gives you.