Windows Server Disconnecting Mac SMB Shares Randomly

The basic plot is I have a Mac Server sharing out files on AFP and SMB. I'm mounting one of those files shares on a Windows 2008 R2 server. Randomly the volume disconnects from the Windows server for a short period, somewhere around 20-30 minutes, and then reconnects. This happens 1-2 times a week.

I'm authentacation to the file share with user account 'Newforma". I have this same user account authentacating for files on other servers as well. At times one server will drop the authentacation while there is no issue with the other server. See the link below for a screenshot.

screenshot: http://redlinetech.files.wordpress.com/2013/04/smb_disconnect_01.jpeg?w=960

The Specs on machines:

Mac Server (dcfiles)

Xserve2,1

10.6.6

Open Directory Master

Services running: Open Directory, AFP, and SMB

Windows Server (STUDIOSDC10)

HP ProLiant DL380 G6

Windows Server 2008 R2 Standard

Service pack 1 x 64

Services running: setup as a Newforma Project Center Server, 9th edition.

My Windows server authenticates to our AD server for login, then files are mounted with authentication from our OD server. This does not cause any problems on the other windows servers and it's the same process that my desktop users have. They authenticate to AD for login, and OD for files. We do not bind AD or OD in any way.

Randomly though when I log into my Windows Server (DC10), There is a red 'X' on my mounted file share. If I double click I get an error message that the network volume doesn't exist. Nothing in the Windows Server Logs that I can find that point to an issue.

I believe the issue is the smb service running on my Mac 10.6 server (dcfiles). I think this because when my files are disconnected from the windows sesrver, I can try to authentacate to the Mac server from my mac desktop with AFP and everything works fine. But If I try to connect to the same file share with smb it doesn't connect. No error messages about wrong passwords or such, it never presents me with a login window. Just says the volume doesn't exist.

When I check the smb logs on the Mac server, I find this repeating over and over, it's pretty standard and in there all the time, even when I"m not having issues.

studiosdc10 (192.168.10.21) connect to service dcfiles initially as user Newforma (uid=1033, gid=20) (pid 69112)

[2013/04/08 09:30:16, 1, pid=69112] /SourceCache/samba/samba-235.5/samba/source/smbd/service.c:close_cnum(1289)

studiosdc10 (192.168.10.21) closed connection to service dcfiles

[2013/04/08 09:30:21, 0, pid=69112] /SourceCache/samba/samba-235.5/samba/source/lib/opendirectory.c:get_opendirector y_authenticator(247)

failed to read DomainAdmin credentials, err=67 fd=172 errno=34

[2013/04/08 09:30:21, 1, pid=69112] /SourceCache/samba/samba-235.5/samba/source/smbd/service.c:make_connection_snum( 1092)

studiosdc10 (192.168.10.21) connect to service dcfiles initially as user Newforma (uid=1033, gid=20) (pid 69112)

My concern is the line that says "failed to read DomainAdmin credentials, err=67 fd=172 errno=34". Though nothing seems to be actually be wrong. I can still authentcate to dcfiles with user 'Newforma' from my Windows server. Just worried that might point to something bigger.

I also run across these errors that have me a little more worried:

[2013/04/08 09:03:14, 0, pid=69112] /SourceCache/samba/samba-235.5/samba/source/lib/opendirectory.c:get_opendirecto ry_authenticator(247)

failed to read DomainAdmin credentials, err=67 fd=137 errno=34

[2013/04/08 09:03:17, 0, pid=231] /SourceCache/samba/samba-235.5/samba/source/lib/util_sock.c:get_peer_addr(1224)

getpeername failed. Error was Invalid argument

[2013/04/08 09:03:17, 0, pid=72621] /SourceCache/samba/samba-235.5/samba/source/lib/util_sock.c:set_socket_options( 261)

Failed to set socket option SO_KEEPALIVE (Error Invalid argument)

[2013/04/08 09:03:17, 0, pid=72621] /SourceCache/samba/samba-235.5/samba/source/lib/util_sock.c:set_socket_options( 261)

Failed to set socket option TCP_NODELAY (Error Invalid argument)

[2013/04/08 09:03:17, 0, pid=72621] /SourceCache/samba/samba-235.5/samba/source/lib/util_sock.c:get_peer_addr(1224)

getpeername failed. Error was Invalid argument

[2013/04/08 09:03:17, 0, pid=72621] /SourceCache/samba/samba-235.5/samba/source/lib/util_sock.c:write_data(562)

write_data: write failure in writing to client 0.0.0.0. Error Broken pipe

[2013/04/08 09:03:17, 0, pid=72621] /SourceCache/samba/samba-235.5/samba/source/lib/util_sock.c:send_smb(761)

Error writing 4 bytes to client. -1. (Broken pipe)

[2013/04/08 09:03:17, 0, pid=72622] /SourceCache/samba/samba-235.5/samba/source/lib/opendirectory.c:get_opendirector y_authenticator(247)

failed to read DomainAdmin credentials, err=67 fd=19 errno=2

[2013/04/08 09:03:42, 0, pid=69112] /SourceCache/samba/samba-235.5/samba/source/lib/opendirectory.c:get_opendirector y_authenticator(247)

failed to read DomainAdmin credentials, err=67 fd=143 errno=34

[2013/04/08 09:05:20, 0, pid=71861] /SourceCache/samba/samba-235.5/samba/source/smbd/nttrans.c:call_nt_transact_ioct l(2537)

call_nt_transact_ioctl(0x1401c4): Currently not implemented.

What I've Already Tried:

- Stopping and restarting the SMB service

- Adding "smb ports = 139” to the smb.conf file on the Mac server

What I'm Considering Trying:

- Deleting and recreating the the 'Newforma' user account from Workgroup Manager on the Mac server

- Making the 'Newforma' user account an admin

- Fearing I might have bigger authentacation issues, demoting my OD master to Stand Alone and re-pormoting to Master.

While I continue to research, document, and monitor the issue ..... any thoughts or ideas would be appreaciated.