[Samba] printing

[Nils Neumann]

I have following configuration :
[global]
  workgroup = testing
  server string = Samba-Server
  security = SHARE
  encrypt passwords = Yes
  map to guest = Bad User
  socket options = SO_KEEPALIVE IPTOS_LOWDELAY TCP_NODELAY
  character set = ISO8859-15
  kernel oplocks = No
[printers]
  comment = All Printers
  path = /var/spool/samba
  hosts allow = 192.168.0.20
  browseable = no
  public = yes
  writeable = no
  printable = yes

1.) My Client has the IP 192.168.0.4, but there is no problem for the client 
to print on my samba server. If I add the line "hosts deny = 192.168.0.4", my 
client can still printing. Is this normal a normal behaviour of the samba ? 
Or is my configuration file wrong ?

2.) If I change the line "public = yes" to "public = no", I can print with the 
client without a password ? Is this normal, too ?

(System : Debian stable/testing, Samba 2.2.3a-6, kernel 2.4.19)

I hope somebody can help!
Nils