Typo error

[cwchong]

approx line 560:

    $classes=ClassInfo::ancestry($className, true);
	foreach($classes as $class) {
		$db = Config::inst()->get($className, "db", CONFIG::UNINHERITED); // <-------
		if(!empty($db) && array_key_exists($sortColumn, $db)) {
			$table=$class;
			break;
		}
	}

the variable in the highlighted line should be $class instead of $className:
$db = Config::inst()->get($class, "db", CONFIG::UNINHERITED);

[UndefinedOffset]

fixed good catch :)