[Samba] Cannot delete files on the share

[Josh]

I am running Samba server on a NAS and use a network share in both 
Windows (XP) as well as Linux clients, though I get a different set of 
problems described below:

1. XP Client -> NAS. On the network share:
- I can read files & directories
- I can create files & directories
- I can rename file & directories
- I can modify/save files & directories
- I cannot delete files/directories

2. Linux client -> NAS. On the network share:
- I can read files & directories
- I can create files & directories
- I cannot rename file & directories
- I cannot modify/save files & directories (*)
- I cannot delete files/directories

* - This is rather strange, because when I edit a file with, say, gedit 
on Linux, I can modify it, but when I try to save it, it tells me 
"permission denied", but at the same time when I look at the net share 
directory, there is a separate/new file created by gedit called 
".goutstream-XXXXX", which is a copy of what should have been saved.

I only get an error message in the Linux client saying "permission 
denied". In the case of the Windows client, I do not get an error 
message at all when I try to delete a file/directory (the file/directory 
simply disappears from Windows Explorer as if I "deleted" it, but when I 
refresh the screen it is still there!).

The user I log in as on the Windows client is "Josh", while in the case 
of the Linux client, this is "josh" (lowercase 'j'), though I am 
identified for the share as "Josh", but have "uid=josh" in my 
/etc/fstab. My smb.conf file is as follows:

[global]
Workgroup = MY.NET
security=user
server string = NAS Server
encrypt passwords = Yes
username level = 8
map to guest = Bad User
null passwords = yes
max log size = 10
name resolve order = bcast wins
socket options = TCP_NODELAY SO_KEEPALIVE SO_SNDBUF=32768 SO_RCVBUF=32768
os level = 32
preferred master = Yes
dns proxy = No
config file = /etc/config/smb.conf
smb passwd file=/etc/config/smbpasswd
username map = /etc/config/smbusers
guest account = guest
force create mode = 0666
force directory mode = 0777
directory mask = 0777
create mask = 0666
oplocks = no
locking = yes
disable spoolss = yes
dos charset = UTF8
force directory security mode = 0000
template shell = /bin/sh
veto files = /.AppleDB/.AppleDouble/.AppleDesktop/:2eDS_Store/Network 
Trash Folder/Temporary Items/TheVolumeSettingsFolder/. at __thumb/. at __desc/
delete veto files = yes
use sendfile = yes
wins support = no
printcap name = /etc/config/printcap
show add printer wizard = no
load printers = yes
print command = /usr/bin/lpr -r -P%p %s

[nas]
comment =
path = /share/HDA_DATA/
browsable = yes
public = yes
invalid users =
read list =
write list = guest,Josh,administrator
valid users = root,guest,Josh,administrator
inherit permissions = yes
[printers]
writable = no
browsable = no
printable = yes
guest ok = yes
path = /mnt/HDA_ROOT/.spool

Any help as to what might be the cause of this rather weird problem is 
mostly welcome! Thanks.