errorهای فارسی کردن phpbb

[hadis81]

سلام دوستان.من phpbb رو نصب کردم و فارسی سازش رو هم اضافه کردم اما error هایی که توی عکس مشاهده می کنید میده.http://rapidshare.com/files/48468259/untitled32.bmp.html
این error ها رو مینویسم که اگه عکس باز نشد ....

[phpBB Debug] PHP Notice: in file /includes/functions.php on line 3270: Undefined index: LEFT
[phpBB Debug] PHP Notice: in file /includes/functions.php on line 3271: Undefined index: RIGHT
[phpBB Debug] PHP Notice: in file /includes/functions.php on line 3299: Cannot modify header information - headers already sent by (output started at /includes/functions.php:2840)
[phpBB Debug] PHP Notice: in file /includes/functions.php on line 3301: Cannot modify header information - headers already sent by (output started at /includes/functions.php:2840)
[phpBB Debug] PHP Notice: in file /includes/functions.php on line 3302: Cannot modify header information - headers already sent by (output started at /includes/functions.php:2840)
[phpBB Debug] PHP Notice: in file /includes/functions.php on line 3303: Cannot modify header information - headers already sent by (output started at /includes/functions.php:2840

خطهایی که ازشون error گرفته اینها هستن:

	if ($config['send_encoding'])
	{
		header('Content-type: text/html; charset=UTF-8');
	}
	header('Cache-Control: private, no-cache="set-cookie"');
	header('Expires: 0');
	header('Pragma: no-cache');

	return;

خواهش میکنم کمکم کنید.