ติดตังเครื่องใหม่ ลง Appserv 2.5.10 ย้ายข้อมูลมาแล้วเกิด Warning: session_start() [function.session-start]

<?
	session_start();
	mysql_connect("127.0.0.1","root","Abc@1234");
	mysql_select_db("crm");
	
	$strSQL = "SELECT * FROM user WHERE U_username = '".trim($_POST['textname'])."'and U_password = '".trim($_POST['textpass'])."'";
	$objQuery = mysql_query($strSQL);
	$objResult = mysql_fetch_array($objQuery);
	if(!$objResult)
	{
		echo "Username and Password Incorrect!";
		echo "<META HTTP-EQUIV=refresh CONTENT=\"2; URL= login.php\">";
	}
	else
	{
		$_SESSION["U_username"] = $objResult["U_username"];
		$_SESSION["U_type"] = $objResult["U_type"];
		@session_write_close();
		if($objResult["U_type"] == "ADMIN")
		{
			header("location:report_service4.php");
		}
		else
		{
		header("location:index.php");
		}
	}
mysql_close();
?>