That's the second time this week!

Firstly, we don't know how fast you're clock the 2051. It can work up to 24mhz last time I used one of these. So, we need to know how fast your cpu is. This influences the instruction timing and your delay timing. Currently, we can see you're doing a delay, but what the actual delay is, is anyone's guess. Depending on your clock speed, you may not be allowing enough setup time for R/!W and RS before you set EN high. At 12MHz, you're ok, any faster you need to add some NOPs. With your delay - one delay does not fit all (unless it is the longest delay required) , for the EN high to low delay, this only needs to be a few cycles at most whereas for the LCD controller delay, this varies depending on the instruction.

LCD_INI:	CLR A
		MOVC A,@A+DPTR
		JZ GO_B1            ;<-zero test here!
		LCALL COM
		LCALL DELAY
		INC DPTR
		SJMP LCD_INI
GO_B1:		RET

So calculate the required delays carefully and re-read the datasheet carefully.