Changed it to...
<?php
$rsGALLERYSUBCS = new WA_MySQLi_RS("rsGALLERYSUBCS",$csdbmysqli,20);
$rsGALLERYSUBCS->setQuery("SELECT NJlinkcatsubgal.NJcatSUBID, NJcategoriesSUB.NJcatSUBTITLE, NJgallery.NJgalleryID, NJgallery.NJdomainID, NJgallery.NJgalleryIMG, NJgallery.NJgalleryTITLE FROM NJlinkcatsubgal INNER JOIN NJcategoriesSUB ON NJlinkcatsubgal.NJcatSUBID = NJcategoriesSUB.NJcatSUBID INNER JOIN NJgallery ON NJlinkcatsubgal.NJgalleryID = NJgallery.NJgalleryID WHERE NJgallery.NJdomainID = $domainID AND NJgallery.NJgalleryDELETE = 2 GROUP BY NJcategoriesSUB.NJcatSUBTITLE ORDER BY RAND()");
$rsGALLERYSUBCS->execute();
?>
...but it's still the same images on every load.
This is available at:
www.nathonjoneswebdesign.co.uk/waterfront/photograph-gallery.php