Failed to load source for: index.php?gallery=1&theme=light
I have found the problem area and have got the gallery to show as follows:
I changed this line in index.php $gallery = get_gallery(get_mediarss_url('gallery=' . $pg_id . '&thumb=62c&full=782p'));
to $gallery = get_gallery(('gallery=' . $pg_id . '&thumb=62c&full=782p'));
Although I believe that this is not a fix, at least it gets us on the right track.