Trying to use an Arduino Duemilanove as an ISP to burn a bootloader to an ATMega

I bought an ATMega1280 processor off of digikey, with the intention of burning a bootloader onto the chip so I could use the Arduino IDE for my project.

I downloaded optiboot, I got the chip soldered to a prototyping board, and I have the SPI pins connected together, as well as pin 10 of my Duemilanove to the reset pin of the ATMega1280. I uploaded the ArduinoISP sketch to my Duemilanove, and after I changed the board to "Arduino Mega (ATMega1280)", I made sure I selected "Arduino as ISP" in the "Programmer" submenu, I then clicked "Burn Bootloader".

I got an error:

"avrdude: Yikes! Invalid device signature. Double check connections and try again, or use -F to override this check."

I've checked my wiring, and I'm pretty sure everything is right, but I'm worried that maybe I didn't get the right ATMega1280. My exact part number is ATMega1280-16AU, and after doing some research, I've discovered that the Arduino Mega actually uses a ATMega1280V-8AU.

I'm really hoping that there's something I can do, I've spent a lot of time so far trying to get this to work.

Some other things that might be helpful: I have a 16MHz external clock wired up to the ATMega1280 as well. The "heartbeat" LED fades in and out as expected, but the "error" LED remains unlit, and the "programming" LED flashes once before I get the error.

Thanks a lot for your help!

Probably the divide-by-8 fuse is set if you bought the "raw" processor.

Useful stuff: http://www.gammon.com.au/forum/?id=11637

This lets you change fuses: http://www.gammon.com.au/forum/?id=11638

(You don't need the SD card for fuse changing).

I got it to work!

It was a really stupid mistake, I had the wrong capacitance on my clock. I had some capacitors wired in parallel instead of series, so everything was off.