Why Cron run twice

[sniperscope]

Hi,

My code running by cron tab. So, Cron executing file every min.

when i test it i figured out that actually cron running more then once, this is weird because it suppose to run file and check the txt file if it is same then stop execution. I have 126 records in my list but if i check the db i see cron send mail more then 8 times. I do not what to do and even what makes this problem.

<?php
include('../../Cn/inc.php');
mysql_select_db($database, $cn);
require_once('jcode.php');
include("Mail.php");

$GetLastRecord 	= mysql_query("SELECT * FROM news ORDER BY id DESC LIMIT 1", $cn) or die(mysql_error());
$RowLastRecord 	= mysql_fetch_assoc($GetLastRecord);
$LastRecordId 	= $RowLastRecord['id'];

$Path 	= "../Rec.txt";
$Open  	= fopen($Path,"r");
$Read  	= fgets($Open);
fclose($Open);

if($Read != $LastRecordId){		
	$Ropen  = fopen($Path,"w");
	$Write = fwrite($Ropen, $LastRecordId);
	fclose($Ropen); // it should write and then close the file to prevent cron never run
                         // this part of script one minute later.

	$LastRecordTitle	= $RowLastRecord['title'];
	$LastRecordBody		= $RowLastRecord['body'];
	$crr_date 			= date("Y/m/d H:m:s");
	$mailFrom			= "[email protected]";

	$smtpinfo["host"] 		= "smtp.example.com";
	$smtpinfo["port"] 		= "587";
	$smtpinfo["auth"] 		= true;
	$smtpinfo["username"] 	= "info";
	$smtpinfo["password"] 	= "123456";

	$MailList	= mysql_query("SELECT mail FROM list WHERE flg='0'", $cn) or die(mysql_error());
	$RowList	= mysql_fetch_assoc($MailList);

	$i = 0;
	do{
		$mailTo      		= $RowList['mail'];
		$mailSubject 		= $LastRecordTitle;
		$returnMailAddress 	= $mailFrom;
		$tm =date("H:i");

		$recipients					= $mailTo;
		$headers["From"]			= "[email protected]";
		$headers["To"]				= $mailTo;
		$headers["Subject"]			= "=?iso-2022-jp?B?".base64_encode(mb_convert_encoding($LastRecordTitle,"JIS","SHIFT_JIS"))."?=";
		$headers["Return-Path"]		= "[email protected]";
		$headers["MIME-Version"]	= "1.0";
		$headers["Content-Type"]	= "text/plain; charset=iso-2022-jp";
		$mailmsg					= mb_convert_encoding($LastRecordBody,"JIS","SHIFT_JIS");

		$mail_object =& Mail::factory("smtp", $smtpinfo);
		$mail_object->send($recipients, $headers, $mailmsg);

		if($i == 60){
			sleep(240);
			$smtpinfo["host"] 		= "smtp.example.com";
			$smtpinfo["port"] 		= "587";
			$smtpinfo["auth"] 		= true;
			$smtpinfo["username"] 	= "info";
			$smtpinfo["password"] 	= "123456";
			$i						= 0;
		}
		$i++;		
	} while($RowList = mysql_fetch_array($MailList));
}
?>