ubuntu8.04 server下samba的奇怪问题~~~

新装的机器。开启是samba服务出现以下现象：
1、机器重启后有时能自动启smb服务，有时不能，需手工启动；
2、samba用户在smb服务自动启动的时候，能顺利访问；在手工启动smb服务的时候不能访问，须重新smbpasswd -a user才可以。
testparm结果如下，请高手解疑!!!
Press enter to see a dump of your service definitions

[global]
server string = %h server (Samba, Ubuntu)
map to guest = Bad User
obey pam restrictions = Yes
passdb backend = tdbsam
passwd program = /usr/bin/passwd %u
passwd chat = *Enter\snew\s*\spassword:* %n\n *Retype\snew\s*\spassword:* %n\n *password\supdated\ssuccessfully* .
unix password sync = Yes
syslog = 0
log file = /var/log/samba/log.%m
max log size = 1000
dns proxy = No
usershare allow guests = Yes
panic action = /usr/share/samba/panic-action %d
invalid users = root

[printers]
comment = All Printers
path = /var/spool/samba
create mask = 0700
printable = Yes
browseable = No

[print$]
comment = Printer Drivers
path = /var/lib/samba/printers