[Samba] shares problem

[empirium]

Hello I have a samba 3 working as a PDC. When I logged in windows 
computer to the domain i have a such problem.
when I run \\samba\public windows say that* shares is unavailable*, but 
when I run \\samba and after that i click folder public everything is ok,
and when I have mapped shares public and i run \\samba\public everything 
is also ok, somebody knows what is wrong?
thanks in advance
luk