This is how I'm calling it:
<script type="text/javascript" language="JavaScript">
$(":jqmData(role='page'):last").on("pageshow", function(event) {
event.preventDefault(); // i just put this in today, but it made no difference
$("#sub", $(this)).popup("open");
});
</script>
Defined:
<div data-role="popup" id="sub" data-history="false" data-theme="e">
I forgot I had posted it before. The last time I noticed it happening I went back to 1.7.1 and it started working. I suppose I should try the current version again.