I've installed the plugin on WP 3.2.1. Works great! But, I needed more control over the links generated by the code. Since I didn't need captions, I decided to use the caption field to store the URL I want to link to and changed the code accordingly.
url : '" . get_bloginfo('url') . "/' with
url : '" . $converted_caption . "/'
in lines 486 and 494 of WPSupersized.php. Didn't know which to change, so did both :)
It isn't the neatest solution, but for now it does the trick. I thought it may be useful to others.
Many R.E.S.T.E.C.P to Sam Dunn and Worldinmyeyes.