samba - Dec 2010 - PDC unreliable - Connection interruptions, many error messages

Dear Group members!

I am having problems with my Samba PDC setup since many months, 
concerning the reliability of the connections from the client to the server.
I am thankful for any hint or advice!!!!

Best regards
Tom

The symptoms on my Windows 7 64bit client:
=======================================
- My Roaming profile in 1 out of 10 times does not get synchronized 
correctly without any obvious reason

- When I edit a document (e.g. word .docx) which is located on a 
samba-share, sometimes when I want to save it to a new (!) file name 
word says that it can't save to the new file name because the document 
is in use by someone else (what can't be since I chose a NEW file 
name!). Word creates the new file name anyway, but it remains 0kb.
When I select "save" again and chose to overwrite the new 0kb file, it
does it without any problem.
When I am working for some hours on a document this occurs in about 2 
out of 10 times that I want to save the document to a new file name. 
(e.g. changing from "File 0.4.docx" to "File 0.5.docx"

- Sometimes the connection to the PDC get's lost in the middle of a 
day's session. Thus all my network drives get disconnected and I have to 
reboot the client to get connected again. If in this time I had Outlook 
2007 opened (my outlook.pst lives on a network share, too), I have to 
close Outlook and reboot to be able to edit anything in Outlook again.


Error messages in /var/log/messages:
=======================================Since day 1 of my Samba-Installation I am
having a lot of errors logged
in my /var/log/messages.
I upgraded from 3.4.3 to 3.5.6, but no change.
I am assuming that those errormessages have to do something with the 
symptoms that I am suffering.
Some of those messages even occur, when a openSUSE-11.3-client uses the 
domain (as a Domain Member)!
Here are some examples (grouped together per occurrence):

smbd[5873]: [2010/04/30 00:31:06,  0] 
rpc_server/srv_netlog_nt.c:603(_netr_ServerAuthenticate3)
smbd[5873]:   _netr_ServerAuthenticate3: netlogon_creds_server_check 
failed. Rejecting auth request from client WORKSTATIONA machine account 
WORKSTATIONA$
smbd[5873]: [2010/04/30 00:31:32,  0] 
lib/util_sock.c:539(read_fd_with_timeout)
smbd[5873]:   getpeername failed. Error was Transport endpoint is not 
connected
smbd[5873]:   read_fd_with_timeout: client 0.0.0.0 read error = 
Connection reset by peer.

smbd[25274]:   getpeername failed. Error was Transport endpoint is not 
connected
smbd[25274]:   write_data: write failure in writing to client 0.0.0.0. 
Error Connection reset by peer
smbd[25274]: [2010/12/29 16:39:25.780295,  0] 
smbd/process.c:79(srv_send_smb)
smbd[25274]:   Error writing 131 bytes to client. -1. (Transport 
endpoint is not connected)
smbd[25238]: [2010/12/29 16:39:25.780682,  0] 
lib/util_sock.c:675(write_data)
smbd[25238]: [2010/12/29 16:39:25.780754,  0] 
lib/util_sock.c:1432(get_peer_addr_internal)

smbd[21246]:   getpeername failed. Error was Transport endpoint is not 
connected
smbd[21246]:   write_data: write failure in writing to client 0.0.0.0. 
Error Broken pipe
smbd[21246]: [2010/12/29 16:39:25.781201,  0] 
smbd/process.c:79(srv_send_smb)
smbd[21246]:   Error writing 75 bytes to client. -1. (Transport endpoint 
is not connected)
smbd[21246]: [2010/12/29 16:39:25.781450,  0] 
lib/util_sock.c:675(write_data)
smbd[21246]: [2010/12/29 16:39:25.781523,  0] 
lib/util_sock.c:1432(get_peer_addr_internal)

WORKSTATIONB enters the network. It is NOT a Domain Member:
smbd[8267]: [2010/12/29 18:14:41.651707,  0] 
rpc_server/srv_netlog_nt.c:475(get_md4pw)
smbd[8267]:   get_md4pw: Workstation WORKSTATIONB$: no account in domain
smbd[8267]: [2010/12/29 18:14:41.651921,  0] 
rpc_server/srv_netlog_nt.c:692(_netr_ServerAuthenticate3)
smbd[8267]:   _netr_ServerAuthenticate3: failed to get machine password 
for account WORKSTATIONB$: NT_STATUS_ACCESS_DENIED

WORKSTATIONA logs on. It IS a domain Member:
smbd[8501]: [2010/12/29 18:21:24.207138,  0] 
rpc_server/srv_netlog_nt.c:714(_netr_ServerAuthenticate3)
smbd[8501]:   _netr_ServerAuthenticate3: netlogon_creds_server_check 
failed. Rejecting auth request from client WORKSTATIONA machine account 
WORKSTATIONA$
smbd[8501]: [2010/12/29 18:21:31.716442,  0] 
auth/auth_sam.c:493(check_sam_security)
smbd[8501]:   check_sam_security: make_server_info_sam() failed with 
'NT_STATUS_NO_SUCH_USER'

QUESTIONS:
=======================================1. Why do I get all those error messages?
2. What do they mean?
3. Are they related with my symptoms?
4. How do I cure this?
5. Could it be that this is related with my other posting ("Samba 
crashes & floods logfiles: "smbd/notify_inotify.c:244(inotify_handler)
-
No data on inotify fd?!")?

My smb.conf
=======================================(all default values and comments are
cropped automatically by SWAT):

[global]
     workgroup = SOMEGROUPNAME.SGN
     server string      max open files = 10000
     add machine script = /usr/sbin/useradd -c SambaMachine -g 
sambamachines -G "" -d /dev/null/ -s /bin/false %u
     logon script = %G.bat
     logon path = \\%N\profiles\%U\%a
     logon drive = z:
     domain logons = Yes
     os level = 255
     preferred master = Yes
     domain master = Yes
     wins support = Yes
     hosts allow = 10.31.40.0/255.255.255.0
     hosts deny = 10.31.40.1
     follow symlinks = No

[homes]
     comment = Home directory
     valid users = %S, %D%w%S
     write list = %S, %D%w%S
     force group = root
     create mask = 0600
     directory mask = 0700
     browseable = No

[profiles]
     comment = Windows User Profiles
     path = /somepath/somedir
     force group = root
     read only = No
     create mask = 0600
     directory mask = 0700
     map archive = No
     map readonly = no
     store dos attributes = Yes
     browseable = No

[netlogon]
     comment = User logon scripts
     path = /var/lib/samba/netlogon
     browseable = No

followed by some custom shares for normal data...