If you have data-popup-options,you cant set data-popup-type, you need set this in data-popup-options,it is the collect of all options setting,it neglet other settings outside data-popup-options
<a class="popup" href="img/1.jpg" data-popup-transition="zoom" data-popup-options="title:'this is a image',ui:'inside',skin:'skinRimless'">
<img src="img/1-thumbnail.jpg" alt="" />
</a>
<a class="popup" href="https://maps.google.com/maps?q=221B+Baker+Street,+London,+United+Kingdom&hl=en&t=v&hnear=221B+Baker+St,+London+NW1+6XE,+United+Kingdom&output=embed" data-popup-type="iframe">iframe</a>
<a class="popup" href="#inline">inline</a>
<div id="inline" style="display: none">
Some Content
</div>
<a class="popup"href="ajax.txt">ajax</a>