unable to burn bootloader

I have a duemilenova with an Atmega 168. Bought an Atmega328P and want to burn the bootloader on it.

I have the 328 on a breadboard without crystal and tried according to http://arduino.cc/en/Tutorial/ArduinoToBreadboard

I have the "ATmega328 on a breadboard (8 MHz internal clock)" option checked under "Tools > Board" and when I choose "Tools > Burn Bootloader > w/ Arduino as ISP" I get the following :

"avrdude: Expected signature for ATMEGA328P is 1E 95 0F Double check chip, or use -F to override this check.

Am I doing anything wrong ? Any help appreciated.

Thanks in advance.

It's not by chance an ATmega328, instead of an ATmega328[u]P[/u], is it?

No, it's a Atmega328P-PU

Thanks for the reply. :D