You should always post code enclosing into <pre> and </pre> tags, it will look as the following:

           ORG     03000H
                MOV     IE,#00H
HERE:		JB	P3.0,HERE
		SETB	P2.0
		SETB	P2.1
		LCALL	WRITEM
		SETB	P2.2
THERE:		JB	P3.1,THERE
		MOV	A,#00H
		MOV	DPTR,#0F000H
		MOVC	A,@A+DPTR
		MOV	P1,A
		MOV	P0,A
NOWHERE:	LJMP	NOWHERE			
WRITEM:		MOV	R1,#02H
		MOV	DPTR,#05000H
		MOV	A,#019H
		LCALL	01FF0H
WRITEM1		CJNE	A,#00H,WRITEM1
                RET

Now your problem: you did not set FCF before JMP 1FF0h. It means, you are jumping into the user flash, instead of boot flash. Check out e.g. http://www.8052.com/forum/read.phtml?id=109730

Jan Waclawek