samba - May 2005 - client mysteriously restricted to read-only

We have a linux samba server running 3.014a. A windows xp machine
sometimes experiences a state where it can only read the shares, and
not write to them. This happens at seemingly arbitrary times. The
machine will go for days at a time functioning normally, and then
suddenly is only allowed read access. Furthermore, there is no
consistent solution. Even a full reboot of both the Samba machine and
the windows machine sometimes does not allow write access.

Below is the output of testparm, and attached is the configuration
file. Anyway ideas would be greatly appreciated.

Thanks,
John



Load smb config files from /usr/lib/smb.conf
Processing section "[clp]"
Processing section "[managers]"
Loaded services file OK.
Server role: ROLE_STANDALONE
Press enter to see a dump of your service definitions

# Global parameters
[global]
        workgroup = CLPMAIN
        server string = samba server
        log file = /var/log/samba/%m.log
        max log size = 50
        keepalive = 0
        socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192
        printcap name = /etc/printcap
        dns proxy = No
        hosts allow = 192.168.1., 192.168.2., 127.
        hide files = /._*/.DS_Store/
        veto oplock files = /*.xls/

[clp]
        comment = CLP Home
        path = /home/clpmain
        valid users = clp, managers
        read only = No
        guest ok = Yes

[managers]
        comment = CLP Managers
        path = /home/managers
        valid users = managers
        read only = No