Changing dropbear port doesn't take effect?

Hi,
  I want to change dropbear to listen on port 33. I edited /etc/init.d/
dropbear, and changed the DROPBEAR_PORT here, but after a "shutdown -r
now", it still comes up on port 22. Also, the top of the dropbear file
says:

"Do not configure this file. Edit /etc/default/dropbear instead."

So, I copied dropbear to /etc/default, along with the modified Port
value, but still no joy.

Anyone have a clue what I'm doing wrong?

Cheers,
Con