[Samba] weird permissions issue

[JJB]

Recently some folks in our engineering group started encountering a 
problem where they can't write to or alter files or folders they did not 
create.

Anyone know what could be causing this type of problem? The users having 
the problem are all in the eng group is /etc/groups. smb.conf for that 
share:

smb.conf:

#smb.conf is the main Samba configuration file. You find a full commented
# version at /usr/share/doc/packages/samba/examples/smb.conf.SUSE if the
# samba-doc package is installed.
# Date: 2005-04-04
[global]
    workgroup = WORKGROUP
    netbios name = int-samba
    server string = int-samba Fileserver
    username map = /etc/samba/smbusers
    map to guest = Bad User
    logon path = \\%L\profiles\.msprofile
    logon home = \\%L\%U\.9xprofile
    logon drive = P:
    add machine script = /usr/sbin/useradd  -c Machine -d 
/var/lib/nobody -s /bin/false %m$
    domain logons = No
    domain master = Yes
    security = user
    idmap gid = 10000-20000
    idmap uid = 10000-20000
    wins support = yes
    remote browse sync = 10.17.100.11
    passdb backend = smbpasswd
    preferred master = yes
    local master = yes
    os level = 255
    socket options = IPTOS_LOWDELAY TCP_NODELAY
    log level = 1
    interfaces = 192.168.1.2/24
    kernel oplocks = yes




## Share disabled by YaST
[homes]
    comment = Home Directories
    valid users = %S
    browseable = No
    read only = No
    inherit acls = Yes
        vfs objects = recycle
        recycle:repository = .Recycler
        recycle:keeptree = Yes
        recycle:versions = Yes

#  File creation mask is set to 0700 for security reasons. If you want to
#    create files with group = rw permissions, set next parameter to 0775.
#    create mask = 0775
#
# Directory creation mask is set to 0700 for security reasons. If you 
want to
#       create dirs. with group=rw permissions, set next parameter to 0775.
#    directory mask = 0700
#    directory mode = 0700


## Share disabled by YaST
# [profiles]
#    comment = Network Profiles Service
#    path = %H
#    read only = No
#    store dos attributes = Yes
#    create mask = 0600
#    directory mask = 0700

## Share disabled by YaST
# [users]
#    comment = All users
#    path = /home
#    read only = No
#    inherit acls = Yes
#    veto files = /aquota.user/groups/shares/
#    comment = Users share (from Miles)
#    inherit acls = Yes
#    path = /data/IT/engineering/Users
#    read only = No
#    valid users = @it @eng
#    force group = eng
#    create mask = 0664
#    directory mask = 0775
#        ##  recycle bin config ##
#    vfs objects = recycle
#    recycle:repository = .Recycler
#    recycle:keeptree = Yes
#    recycle:versions = Yes

## Share disabled by YaST
# [groups]
#    comment = All groups
#    path = /home/groups
#    read only = No
#    inherit acls = Yes

## Share disabled by YaST
# [printers]
#    comment = All Printers
#    path = /var/tmp
#    printable = Yes
#    create mask = 0600
#    browseable = No

## Share disabled by YaST
# [print$]
#    comment = Printer Drivers
#    path = /var/lib/samba/drivers
#    write list = @ntadmin root
#    force group = ntadmin
#    create mask = 0664
#    directory mask = 0775

[nobackup]
    comment = nobackup
    inherit acls = Yes
    path = /data/nobackup
    read only = No
    valid users = mainshare @it @webdev
    create mask = 0664
    directory mask = 0775

[it]
    comment = IT
    inherit acls = Yes
    path = /data/IT/IT-share
    read only = No
    valid users = @it
    force group = it
    create mask = 0664
    directory mask = 0775
        ##  recycle bin config ##
    vfs objects = recycle
    recycle:repository = .Recycler
    recycle:keeptree = Yes
    recycle:versions = Yes

[htdocs]
    comment = Intranet Web Area
    inherit acls = Yes
    path = /data/IT/htdocs
    read only = No
    valid users = @it @webdev
    force user = wwwrun
    force group = mycompany

    create mask = 0664
    directory mask = 0775

        ##  recycle bin config ##
    vfs objects = recycle
    recycle:repository = .Recycler
    recycle:keeptree = Yes
    recycle:versions = Yes

[svn]
    comment = Subversion repositories
    inherit acls = Yes
    path = /data/IT/svn/
    read only = Yes
    valid users = @it
    force group = mycompany
    create mask = 0664
    directory mask = 0775

[mysql]
    comment = Mysql databases
    inherit acls = Yes
    path = /data/IT/mysql
    read only = Yes
    valid users = @it
    force user = mysql
    force group = mysql
    create mask = 0660
    directory mask = 0775

[backups]
    comment = MySQL Database backups
    inherit acls = Yes
    path = /data/IT/backups
    read only = No
    valid users = @it
    force group = it
    create mask = 0664
    directory mask = 0775

[eng-parent]
    comment = Parent of all engineering shares
    inherit acls = Yes
    path = /data/IT/engineering/
    read only = No
    valid users = @it
    force group = eng
    create mask = 0664
    directory mask = 0775

[engweb]
    comment = Engineering share
    inherit acls = Yes
    path = /data/IT/engineering/engweb
    read only = No
    valid users = @it @eng
    force group = eng
    create mask = 0664
    directory mask = 0775
        ##  recycle bin config ##
    vfs objects = recycle
    recycle:repository = .Recycler
    recycle:keeptree = Yes
    recycle:versions = Yes

[devtools]
    comment = Engineering Development Tools (from Miles)
    inherit acls = Yes
    path = /data/IT/engineering/DevTools
    read only = No
    valid users = @it @eng
    force group = eng
    create mask = 0664
    directory mask = 0775
        ##  recycle bin config ##
    vfs objects = recycle
    recycle:repository = .Recycler
    recycle:keeptree = Yes
    recycle:versions = Yes

[engdownloads]
    comment = Engineering Downloads
    inherit acls = Yes
    path = /data/IT/engineering/Downloads
    read only = No
    valid users = @it  @eng
    force group = eng
    create mask = 0664
    directory mask = 0775
        ##  recycle bin config ##
    vfs objects = recycle
    recycle:repository = .Recycler
    recycle:keeptree = Yes
    recycle:versions = Yes

[engineering]
    comment = Engineering share (from Miles)
    inherit acls = Yes
    path = /data/IT/engineering/Engineering
    read only = No
    valid users = @it @eng
    force group = eng
    create mask = 0664
    directory mask = 0775
        ##  recycle bin config ##
    vfs objects = recycle
    recycle:repository = .Recycler
    recycle:keeptree = Yes
    recycle:versions = Yes

[pcom]
    comment = PCOM share (from Miles)
    inherit acls = Yes
    path = /data/IT/engineering/PCOM
    read only = No
    valid users = @it @eng
    force group = eng
    create mask = 0664
    directory mask = 0775
        ##  recycle bin config ##
    vfs objects = recycle
    recycle:repository = .Recycler
    recycle:keeptree = Yes
    recycle:versions = Yes

[users]
        ##  recycle bin config ##
        vfs objects = recycle
        recycle:repository = .Recycler
        recycle:keeptree = Yes
        recycle:versions = Yes

[mainshare]
    comment = mainshare
    inherit acls = Yes
    path = /data/mainshare
    read only = No
    valid users = mainshare @it @eng @mycompany @webdev
    force user = mainshare
    force group = mycompany
    create mask = 0664
    directory mask = 0775
        ##  recycle bin config ##
    vfs objects = recycle
    recycle:repository = .Recycler
    recycle:keeptree = Yes
    recycle:versions = Yes

[Legacy_Data]
        comment = Legacy Access DB
        inherit acls = Yes
        path = /data/mainshare/Manufacturing/Legacy
        inherit acls = Yes
        read only = No
        valid users = mainshare @it @eng @mycompany @webdev
        force group = mycompany
        create mask = 0664
        directory mask = 0775


[Media]
        comment = mainshare
        inherit acls = Yes
        path = /data/media
        read only = No
        valid users = mainshare @it @eng @mycompany @webdev
        force user = mainshare
        force group = mycompany
        create mask = 0664
        directory mask = 0775
        ##  recycle bin config ##
        vfs objects = recycle
        recycle:repository = .Recycler
        recycle:keeptree = Yes
        recycle:versions = Yes



[Retrospect]
        comment = mainshare
        inherit acls = Yes
        path = /media/disk/retrospect
        read only = No
        valid users = @it @eng @mycompany @webdev
        force group = mycompany
        create mask = 0664
        directory mask = 0775
        ##  recycle bin config ##
        vfs objects = recycle
        recycle:repository = .Recycler
        recycle:keeptree = Yes
        recycle:versions = Yes

[Doc_IN]
        comment = MFG, Eng Doc deposit
        inherit acls = Yes
        path = /data/docdeposit
        read only = No
    valid users = mainshare @it @eng @mycompany @webdev       
    force user = docdepositor
        force group = mycompany
        create mask = 0664
        directory mask = 0775
        ##  recycle bin config ##
        vfs objects = recycle
        recycle:repository = .Recycler
        recycle:keeptree = Yes
        recycle:versions = Yes