Samba access issue in Windows 7

[ldi9999]

I'm having an issue with samba accessing from Windows 7 Ultimate 64bit version.

I have two shares in smb.conf, one has read only access "External" for user without password, another one is r/w "ExternalRW" for users with password. here is the sbm.conf:

$this->bbcode_second_pass_code('', '
[global]
workgroup = WORKGROUP
server string = ALARM
netbios name = ALARM
security = user
null passwords = yes
map to guest = bad user
log file = /var/log/samba/%m.log
max log size = 50
dns proxy = no
socket options = TCP_NODELAY IPTOS_LOWDELAY SO_KEEPALIVE SO_RCVBUF=131072 SO_SNDBUF=131072 SO_KEEPALIVE

[ExternalRW]
path = /media/External/
read only = no
public = yes
writable = yes
guest ok = no

[External]
path = /media/External/
read only = yes
public = yes
writable = no
guest ok = yes
')

I could see both shares under Network in Windows 7. Read only share "External" works as expected. However, I'm having issue accessing RW share "ExternalRW". When I double clicked on "MediaRW", windows pop up window asking for user id and password. No matter how I enter, I always get "access denied" error and never be able to access the share.

Any idea? Thanks.

[WarheadsSE]

And you've verified the username is in the smbpasswd blah blah.. ?

[ldi9999]

I followed the guide
$this->bbcode_second_pass_code('', 'Now we create a user that will be used for guest access. Use all defaults and pick a password.
adduser pcguest

Add the new guest account to samba. (Use a blank password since it's a guest account).
smbpasswd -a pcguest')

I did tried user pcguest, guest, root.. anything I could think of.

[WarheadsSE]

guest = bad user, remember?

maybe a valid user added might help...