I tried your sketch on a Bobuino with a 1284 chip, the speaker buzzed but nothing more. The board is found halfway down this page. Cross Roads Electronics
This may be asking too much but, would you consider making your library work with the 1284P? I have built a few boards using the chip.
This page may help you in the process if your interested. Arduino on ATmega1284P | maniacbug
I will be happy to test for you of course. 