samba - May 2004 - I'm losting the samba's shares automatically of time in time.. why?

Hi all

I create some shares here and everything is right
for begin I made a 'chmod -R 777 /share' to make sure that all users
will be access
and ok, all users can use the share

but sometimes the shares seems to be broken...
nobody can use the share...

to recover again, I must type chmod -R 777 again...
'service smb restart' do not work... only 'chmod -R 777'...

someone can help me with this ???

thanx

Fl?vio Henrique