Help - NAS Access from Subsonic has stopped working

[ideality]

I have been using Subsonic for years (with iSub as the iPhone client). This has been working for years.

The basic setup is simple. I have one computer (named Grapefruit and running Windows XP) which serves Subsonic. It points to directories on the machine itself (D:\media) as well as to a NAS that's on the network (\\nashama\media\media-av).
Usually, when I rip a new CD, I rip it to the d:\media directory and then some time later, I move it to the NAS.

This has worked perfectly until a day or two ago. I.e. Subsonic served both directories. (I actually simplified this a bit, in that there is more than these two directories involved, but the principle is correct). This has worked great for years.

Until this weekend. Now, Subsonic only shows the music that came from the drive on the local machine (d:\media).

Here is the summary. There are about 80,000 files on the NAS. About 5,000 locally. I can logon to subsonic (using a browser/chrome to localhost:54322 or it's name on the internet). When I do an index, it shows that there are about 85,000 files in total. But the only files that are actually shown are the ones from the local drive. "About" shows that Lucene has finished indexing (showing about 85,000 files). But, the only files that actually show up on the left hand side are the ones that came from the local drive. Same for iSub. The windows account I use to run the server has the "logon as a service" priv. As mentioned, this has been working for years, and just now stopped working correctly. The NAS is running fine for all other applications.

I just looked at the log, and I get misc errors, mostly having to do with failing to find cover art for some albums. It is doing this for albums that are on the NAS.
I also just saw a warning (in the log file and in the About box):

[[2012-02-06 10:38:55,940] WARN FileUtil - Failed to list children for \\nashama\media\media-av\learn
[2012-02-06 10:41:27,909] WARN FileUtil - Failed to list children for \\nashama\media\media-av\music
[2012-02-06 10:41:27,909] WARN FileUtil - Failed to list children for \\nashama\media\media-av\music\Joni Mitchell\Song to a Seagull
[2012-02-06 10:41:27,909] WARN FileUtil - Failed to list children for \\nashama\media\media-av\music\Ahmed Tijani & Friends\Praise

I don't know why these errors are occurring.

I also added a few smaller directories on the NAS, and those seem to work OK. e.g. \\media\books-on-tape, and I can listen to Harry Potter just fine. So, it seems to only be a problem with very large directories.

Any thoughts? Or suggestions?

.. Michael