samba - Jul 2013 - SAMBA not broadcasting server info

Up until a few days ago, I had SAMBA running just fine on several
different systems, but very recently on of the server has quit announcing
itself to the newtwork.  Smbd, nmbd, and winbindd are all running on the
server, and the machines on the network can all still reach the shares on
the system, but an attempt to browse for the server and its available shares
from a client PC does not produce a listing of the system.  The other
systems show up just fine.  I can't find any errors of any sort in the logs.
I have made a number of changes to the system recently, including an upgrade
to Debian Wheezy, but I cannot figure out where the issue might have arisen.
Where can I look for the issue?  I have not made any changes to the config
file, but here it is, anyway:

AID-Server:/var/log# cat /etc/samba/smb.conf
# Samba config file created using SWAT
# from UNKNOWN (192.168.1.121)
# Date: 2013/07/27 09:43:41

[global]
        workgroup = HOME
        map to guest = Bad User
        guest account = lrhorer
        printcap name = cups
        disable spoolss = Yes
        mangle prefix = 6
        domain master = No
        ldap ssl = no
        idmap config * : range = 
        idmap config * : backend = tdb

[Server-Main]
        path = /RAID/Server-Main/
        valid users = lrhorer
        admin users = lrhorer
        read only = No
        guest ok = Yes

[TiVo-Music]
        path = /RAID/Music/
        admin users = lrhorer
        read only = No
        guest ok = Yes

[Video]
        path = /RAID/Recordings/
        admin users = lrhorer
        read only = No
        guest ok = Yes

[Leslie]
        path = /RAID/Personal_Folders/Leslie/
        valid users = lrhorer, "Leslie A Rhorer"
        admin users = lrhorer, "Leslie A Rhorer"
        read only = No
        guest ok = Yes
        strict locking = No

[Liza]
        path = /RAID/Personal_Folders/Liza/
        valid users = lgates
        admin users = lgates
        read only = No
        guest ok = Yes
        strict locking = No

[Tiffany]
        path = /RAID/Personal_Folders/Tiffany/
        valid users = tgates
        admin users = tgates
        browseable = No
        strict locking = No
        available = No

[V-Edit]
        path = /V-Edit/
        admin users = lrhorer
        read only = No
        guest ok = Yes

[Photos]
        path = /RAID/Photos/
        admin users = lrhorer
        read only = No
        guest ok = Yes

[HP_940C]
        path = /home/smbprint
        printer admin = lrhorer
        create mask = 0700
        guest only = Yes
        guest ok = Yes
        printable = Yes
        print ok = Yes

[DVD_Rip]
        path = /RAID/DVD
        valid users = lrhorer
        read only = No
        guest ok = Yes

[Thermostat]
        path = /usr/share/thermostat
        username = root
        valid users = lrhorer
        admin users = lrhorer
        read only = No
        guest ok = Yes

[html]
        path = /var/www
        valid users = lrhorer
        admin users = lrhorer
        read only = No
        guest ok = Yes