I did post for help about my original problem but nobody reply, so I try another approach:
I had a problem with the Arduino BT start-up after upload the Sniff mode, so I try to put back the Booth Loader (.hex) in hope it can be revised as before.
One technical support said that the: \arduino-0015\hardware\bootloaders\bt\ATmegaBOOT_168.hex is the same one when the Arduino BT was shipping ... can anyone confirm it? Because I did use ARV Studio 4.13 to program in the Flash (Atmega168), but it still can not work as before!
If someone knows the original ATmegaBOOT_168.hex please provide.
Thank in-advanced :-/