Thanks. Shortcodes Ultimate is a very fine and handy tool. Thank you for your efforts to develop it.
Easiest way is to replace every instance of
<div class="postbox closed"> with
<div class="postbox"> in frontpage-slideshow.php – that simply opens all the closed boxes. I’ve had the same problem on nearly all blogs with custom themes where I’ve used the slideshow. I suspect there’s a JS conflict somewhere or other issue, but simply opening the boxes is the quick and easy fix (for me at least).