General Support: How do you re-order the photos in plog-sitemap.php

I've upgraded my gallery with a great deal of difficulty from revision 549 to the latest RC1. I wanted to use my old templates but couldn't get everything working properly so I've stuffed my html into the plog-sitemap.php file to get it to look like the rest of my site. Unfortunately the xml won't validate but at least I've got a list of all the photos on a web page.

I changed the display to show the picture caption name instead of the filename in the sitemap. All the collections and albums seem to be in alphabetical order but the photos aren't. How do I adapt plog-sitemap.php to list the images below their respective albums in alphabetical order using the caption?