Bootloading error: Invalid signature (0x000000)

Hi.
I'm trying to burn a bootloader on to two new Atmega328p chips I recently bought. I always get an invalid signature error.
In a terminal window I write: (I know this isn't for actually burning the bootloader)

avrdude -c usbtiny -p m328p -v -F

and I get:

Programmer Type : USBtiny
         Description     : USBtiny simple USB programmer, http://www.ladyada.net/make/usbtinyisp/
avrdude: programmer operation not supported

avrdude: Using SCK period of 10 usec
avrdude: initialization failed, rc=-1
avrdude: AVR device initialized and ready to accept instructions
avrdude: Device signature = 0x000000
avrdude: Yikes!  Invalid device signature.
avrdude: Expected signature for ATMEGA328P is 1E 95 0F

I have also tried using Arduino as ISP with the same results.

Before I tried burning the bootloader to the chip using the Arduino IDE (programmer set to USBtiny) I wrote the line above in a terminal window and it read the fuse bits successfully.
Did I brick my atmega chips?

-Thanks.

If the chip has an Arduino bootloader already, OR you are putting on an Arduino bootloader, you need the Arduino clock circuitry or a valid substitute.

I had the same problem with an Atmega328p bought with bootloader already written.
I got "Invalid device signature" all the time.
In my case, it proved that the 16 MHz Crystal + 22 pF external oscillator, connected to this Atmega328p, did not work.
See: Arduino Uno R3 as a true ISP programmer for any AVR - #7 by simplex - Microcontrollers - Arduino Forum for more details about how I fixed the problem.

It's working now. I'm not entirely sure what the problem was, I just removed the circuit from the breadboard and rebuilt it. Also I ditched the Arduino IDE, downloaded optiboot hex files and used avrdude in terminal. They both work perfectly now in my Uno.
Thanks.

arnarg:
It's working now. I'm not entirely sure what the problem was, I just removed the circuit from the breadboard and rebuilt it. Also I ditched the Arduino IDE, downloaded optiboot hex files and used avrdude in terminal. They both work perfectly now in my Uno.
Thanks.

Maybe it was a bad connection on the breadboard. That happens all the time.