RP is correct, the default Nano bootloader is the one from the Duemilanove.
I reflashed my Nano with OptiBoot (the bootloader used on the Uno) and have had no problems. I've now got OptiBoot running on all my boards & standalone chips; now I can leave the board at "Uno" and not have to switch every time I move between projects.
I understand how to put Optiboot on a 328 chip. I use the Uno board as explained on the site.
How do you burn a new bootloader to a chip on a surface mount board such as Nano?
How do you burn a new bootloader to a chip on a surface mount board such as Nano?
The exact same way. D10 on the Arduino running the bootloader upload script to the reset pin on the Nano, D11 - 13 from the uploader to pins D11 - 13 on the Nano, ground to ground, and 5v to 5v.