Mac samba connection to Server 2003 error -23

Hi Experts! I have a doozy of a connection issue between MAC and Windows Server 2003. I have searched for possible solutions on EE, but nothing seems to work.

Here is the network structure:

We have 2 servers at the office, both Server 2003 (one primary and one secondary domain controller).
We have 22 PCs, all running XP and two MACs running 10.4

Both MACs used to be able to connect to both servers using "Connect to Server" and typing smb://

As of recently, one server (primary domain controller) will not connect (console error below from each machine). This happens to both MACs at the same time. Usually late in the afternoon, both MACs can connect again OK.

The other server (secondary domain controller) has no problems with MAC connections.

One MAC reports this console error:
mount_smbfs: can't get server address: syserr = Network is down /XRefStm encountered but not yet supported.

And the other MAC reports:
mount_smbfs: negotiate phase failed: syserr = Software caused connection abort.

Because of the timing of connection failure/success, I'm wondering if another device on my workstation is gaining delegation and removing the MAC connection ability? I know, it's a long shot. Thanks for the help.
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How many windows licenses do you have on the PDC?

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t15robertsAuthor Commented:
Good question. I believe we CALs for 25.... how would I confirm that?

control panel -> licensing -> check quantity there. Also check the logs and see if any license/ access errors.
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t15robertsAuthor Commented:
OK, so by now you can tell I'm not a true IT specialist. I have attached a screenshot of the Licensing screen (it doesn't list any CAL quota). Also, I checked the event viewer on the DC, but no warnings or errors occur in the same time pattern as these problems.
when you have time, help me answer this question

Trying to get some points
Hi t15roberts

Are you using Windows Server 2003 Standard? Have you tried accessing your system using AFP?

i.e. afp://server/mac_share ? You will need to install File and printer services for Macintosh on the server first. The make a new Mac share using the Shares console under Computer Management for your existing shared folder. I've found this to be more reliable that SMB mounts.
t15robertsAuthor Commented:
AFP is not a solution, as adding the Windows component on the server results is a installation error. We're running MS Server 2003 Standard R2.

Weird thing is, it used to work flawlessly. Your theory around CAL licensing may be on track -- early in the AM and late in the day, before/after all XP machines are logged in, the MACs can connect.

DO you have a suggestion to verify that theory?
nappy_dThere are a 1000 ways to skin the technology cat.Commented:
What mode is your server set to for licensing? Per user or per server?

Set you servers to use per server mode and then get additional licenses.
t15robertsAuthor Commented:
Thank you for the comments. Since SnowWolf first mentioned the CAL licensing, I am awarding the points. The solution was to purchase additional licenses. Thank you!
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