private static function _GetInt4d($data, $pos)
	{
		// FIX: represent numbers correctly on 64-bit system
		// http://sourceforge.net/tracker/index.php?func=detail&aid=1487372&group_id=99160&atid=623334
		// Hacked by Andreas Rehm 2006 to ensure correct result of the <<24 block on 32 and 64bit systems
		$_or_24 = ord($data[$pos + 3]);
		if ($_or_24 >= 128) {
			// negative number
			$_ord_24 = -abs((256 - $_or_24) << 24);
		} else {
			$_ord_24 = ($_or_24 & 127) << 24;
		}
		return ord($data[$pos]) | (ord($data[$pos + 1]) << 8) | (ord($data[$pos + 2]) << 16) | $_ord_24;
	}