I have an Atmel AT89C51RB2 chip that I am trying to program using Hyperterminal. When I put the chip into the ISP mode, the bootloader runs and I can type commands and get valid responses from the chip. But, when I download a .hex program file, everything seems to work but the program won't run. Is there a step that I am missing?

(Note that I can program the chip successfully using the FLIP software provided by Atmel. But, I want to be able to do it without using FLIP).

Any suggestions? Thanks.