[Samba] confusion about shares and rights

[J. Echter]

Hi,

i have some shares defined in my smb.conf, but now i experience rights 
issues.

a share looks like this:

[share]
    path = /mnt/share
    guest ok = yes
    writeable = no
    public = no
    write list = @ntusers
    read only = no

this settings i have set since i experience problems.

before it looked like this and worked:

[share]
    path = /mnt/share
    guest ok = yes
    writeable = yes
    public = no
    write list = @ntusers

since a few days i have the problem that i can copy files to the share, 
but can't delete or modify them.

i have some other shares i want to be used only by some picked people.

these shares look like this:

[bau]
    path = /mnt/share2
    guest ok = no
    writeable = no
    public = no
    valid users = tom peter Administrator
    read only = no

same issue there.

my smb.conf global section:

[global]
    printing = bsd
    netbios name = PDC
    server string = PDC (%h)
    workgroup = workgroup
    interfaces = eth0,lo
    security = user
    encrypt passwords = true
    map to guest = bad user
    local master = yes
    preferred master = yes
    domain master = yes
    domain logons = yes
    add user script = /usr/sbin/useradd -m '%u' -g ntusers -G ntusers -s 
/bin/false
    delete user script = /usr/sbin/userdel -r '%u'
    add group script = /usr/sbin/groupadd '%g'
    delete group script = /usr/sbin/groupdel '%g'
    add user to group script = /usr/sbin/usermod -G '%g' '%u'
    add machine script = /usr/sbin/useradd -d /var/lib/nobody -g 100 -s 
/bin/false -M %u
    logon path = \\%L\profile\%U
    logon script = %U.bat
    logon drive = H:
    hide files = /desktop.ini/ntuser.ini/NTUSER.*/Thumbs.db/
    panic action = /usr/share/samba/panic-action %d


i hope you can help out. im still wondering why this has worked before :(

greetings juergen.