$sql = db_query("SELECT punkte FROM ".$db_prefix."_mklickrally WHERE uid= ".$userid." ORDER BY uid DESC LIMIT 1");

oder

$sql = db_query("SELECT punkte FROM ".$db_prefix."_mklickrally WHERE punkte=".$_SESSION['uid']." ORDER BY uid DESC LIMIT 1");

irgendwie in den dreh mal denk anstoß