Arduino BT bootloader problem

Hello,

I am new to arduino as well as hardware. Recently, my arduino BT suddenly fails to be detected and programmed in windows, and I found out the reset pin(pin 7) always go high and low repeatly. I decide to upload the bootloader using the Parallel Port Programmer http://www.arduino.cc/en/Hacking/ParallelProgrammer?from=Main.ParallelProgrammer.

And I follow the step decribed in here http://www.uchobby.com/index.php/2007/09/12/how-to-update-the-arduino/ with replaced the bootloader to bt one.

My problem is that I always face verification error

avrdude: verifying ... avrdude: verification error, first mismatch at byte 0x3800 0x0c != 0xff avrdude: verification error; content mismatch

avrdude: safemode: hfuse changed! Was df, and is now ff Would you like this fuse to be changed back? [y/n]

What should I do?

Thanks a lot, Mark