Problem with Writing the code on Controller

I am working on AT89C51, the problem is that although my assembly code is working perfectly on the pinnacle simulator it gives a verification failed error when I try to write it on the programmer using ezdl4 s/w.

Simple programs with commands to send and recieve data on the serial port work fine and get written on the controller, but when I use commands like ACALL or MOVC in my code it gives me the verification failed error.

Example of a Code working on the programmer.

ORG 0H

MOV TMOD,#20h
MOV TH1,#98h
MOV SCON,#50H
SETB TR1

ECHO:

RECV: JNB RI,RECV
MOV A,SBUF
CLR RI

MOV SBUF,A
SEND: JNB TI,SEND
CLR TI

SJMP ECHO

END

Example of a Code not Working

MOV TMOD,#20h
MOV TH1,#98h
MOV SCON,#50H
SETB TR1

MOV DPTR,#MYDATA

H_1:
CLR A
MOVC A,@A+DPTR
JZ B_1
ACALL SEND
INC DPTR
SJMP H_1

SEND: MOV SBUF,A
JNB TI,$
CLR TI
RET

MYDATA: DB "SeriaL Data Transmission 123",0H

B_1:
HERE:SJMP HERE
END

Note: I have a 12Mhz crystal and so i am using a baudrate of 300bps.

Could anyone please tell me whats the problem asap.
Thank you