[Samba] Red X and guest user message in logs

[Marco De Vitis]

Hello,
I have a Debian Sarge machine running Samba 3.0.14a as PDC and file server.
Everything runs smoothly, except for a random problem: users (on 
Win2000Pro clients) are often seeing a red cross on the main network 
share, as if it was disconnected. This red X seems to come and go at random.

The red cross would not be a big issue itself, but it has an annoying 
consequence: when it appears, Windows thinks the connection is down, so 
if you save a file on the share while the red X is there you get an 
error dialog telling something like "The connection to the server has 
been reset. The file cannot be saved." (recalling from memory and 
translating from Italian, so the actual English message might be very 
different).
The file is saved anyway, but users are obviously alarmed by the message.

I had a look at my Samba logs (level 2) around the time when an user 
told me he noticed the red cross, but didn't find anything special, 
exception made for the following message:

> [2005/11/25 17:14:51, 2] smbd/service.c:make_connection_snum(314)
>   guest user (from session setup) not permitted to access this share (COMMESSE)

The user was already authenticated on the domain, and didn't logoff, so 
I can't understand where does this guest access come from.
Can this message be related to my problem?

Here follows an excerpt from my smb.conf, as returned by testparm, with 
some more or less sensible data <omitted>.
BTW, the log file where I found that message was named 
"<client_name>..log", which is correct (see log file setting below).

I really hope someone can give me some clues, as this has been going on 
for months now.
Thanks in advance.

---------------------
[global]
         unix charset = UTF8
         workgroup = <domain name>
         server string = Server Linux, Samba %v
         passdb backend = tdbsam
         log level = 2 vfs:2
         syslog = 0
         log file = /var/log/samba/%m.%U.log
         max log size = 0
         logon script = netlogon.bat
         logon path = \\%L\profiles\%U
         logon drive = Z:
         domain logons = Yes
         os level = 64
         preferred master = Yes
         domain master = Yes
         enhanced browsing = No
         create mask = 0664
         directory mask = 0775
         hosts allow = 127.0.0.1, 192.168.1.0/255.255.255.0
         ea support = Yes
         hide files = /desktop.ini/.DS_Store/
         veto oplock files = /NTUSER.DAT/
         map archive = No
         store dos attributes = Yes
         dos filemode = Yes

[netlogon]
         path = /home/netlogon
         browseable = No

[profiles]
         path = /home/samba/profiles
         read only = No
         create mask = 0600
         directory mask = 0700
         browseable = No

[COMMESSE]
         path = <a valid path>
         invalid users = <one username>
         force user = <another username>
         read only = No
         vfs objects = recycle
         recycle:exclude = ~$* ~*.doc *~*.tmp *.bak
         recycle:touch = yes
         recycle:versions = yes
         recycle:keeptree = yes
         recycle:repository = .cestino
---------------------

-- 
Ciao,
   Marco.