-------- Message original --------

> I added Dropbear SSH server to m0n0wall.
> I used "Web GUI" "General Setup" to create the user
> "admin" and its password.

 From the README file:

"There is no username / password management in this module. At boot time 
the password for "root" is set to the m0n0wall admin password.
Note that this password synchronization only takes place at boot time. 
When the m0n0wall admin password is changed, a reboot is required to 
change the root password."

So, login as 'root' instead of 'admin' (with the same password). That 
should work.

-- Vincent