Is it possible the avrdude.conf in the 0013 Linux package has not been upgraded to include the Atmega328p? I get avrdude errors when I try to use it. I'm using Ubuntu Intrepid.
Update - I checked the avrdude.conf in arduino-0013/hardware/tools and it doesn't have a m328p section. the same file in the windows package does have it. I got my system to work by replacing avrdude.conf with the one from the Windows package.
My system had copies of avrdude.conf in /etc; in the arduino-0013 directory set; and in /usr/local/etc, so I had to make sure all of the them were replaced, since I wasn't sure which one was being used.