USB Bootloader for LPC2148

Hello all, I have programmed LPC2148 for using USB as secondary boot loader. Code was given by NXP only.
It says, when LPC2148 is connected to PC it will open flash memory as mass storage device and flash will be shown in .bin file.
Till this everything is fine.
To update the firmware one should delete that .bin file and copy new one there. I did the same. Code includes simple LED blink. But on giving power cycle code is not working.
If I program BLinkLed code using UART ISP it works correctly.

Document says in USB boot loader's firmware user code start sector should be 2. I did that also.

Do I need to change any settings is my blinkLed firmware so that code will get stored from 2nd sector? or is there any procedure?

Thank you..