samba guest access from a different network

[Luca Ferrari]

Hi all,
in my smb.conf file I've got:

[Test]
        path = /mnt/test
        writeable = yes
        guest ok = yes
        browsable = yes
        available = yes

and I can access the share from the local network (192.168.2.) but not from 
another network (192.168.1.) or better from the latter I cannot access from a 
win/mac pc, while from a linux box I can access. Each time I try to access 
from a windows pc on the 192.168.1 network I'm prompter for a username and 
password, and of course "guest" does not work. From a linux box on the same 
network I can access without any username and password. I've checked the 
server and there is not a firewall rule, so what can be the problem?

Thanks,
Luca