I tried using the following code (from this site) and it behaves exactly the same , it sends the output three more times after i power down the circuit.
so what do the experts say . is it the hardware? something i need to do in the RS232 circuit?

;*****************************************************************
;This is an example of polled transmit
;*****************************************************************
;
$MOD51
;
CR EQU 0DH
LF EQU 0AH
;
	ORG 	0
	LJMP 	MAIN
;
	ORG 	100H
MAIN:   LCALL 	SERINIT
	MOV 	DPTR,#HELLO
	LCALL 	TEXT_OUT
	MOV 	DPTR,#MSG1
	LCALL 	TEXT_OUT
	MOV 	DPTR,#MSG2
	LCALL 	TEXT_OUT
LOOP: 	AJMP 	LOOP 				;STOP HERE
;*****************************************************************
;Other Serial Messages
;
HELLO: 	DB 'Hello World',CR,LF,0
MSG1: 	DB 'I am sending messages to my terminal!',CR,LF,0
MSG2: 	DB 'This is fun..',CR,LF,0
;*****************************************************************
SERINIT: ;Initialize serial port
	CLR 	TR1
	CLR 	TI
	CLR 	RI
	MOV 	SCON,#01011010B 	;TI SET INDICATES TRANSMITTER READY.
					;MODE 1 REN
	MOV 	TMOD,#00100001B 	;TIMER 1 MODE 8 BIT AUTO RELOAD
	MOV 	TH1,#0FDH 		;TIMER RELOAD VALUE
	SETB 	TR1 			;START TIMER
	MOV 	DPTR,#SINIT
	LCALL 	TEXT_OUT
	RET
;
SINIT: 	DB 	CR,LF
	DB 	'Serial Port Initialized! '
CRLF: 	DB 	CR,LF,0
;*****************************************************************
TEXT_OUT:
WT1: 	CLR 	A
	MOVC 	A,@A+DPTR
	INC 	DPTR
	JZ 	WT2
	LCALL 	CHAR_OUT
	AJMP 	WT1
WT2: 	RET
;*****************************************************************
CHAR_OUT:
	CLR 	TI
	MOV 	SBUF,A
	JNB 	TI,$
CORET: 	RET
;*****************************************************************
END