[Samba] High CPU usage on 3.2.3

[Ryan Bair]

I just noticed I'm getting some pretty extreme CPU usage on my Samba
server when transferring files. The Samba server has a quad core
2.0gHz Core2. During transfers, CPU use spikes to 100-200% with a
throughput around 30MB/s.

I'm using the registry config backend.

[global]
        use kerberos keytab = True
        server string = X
        dns proxy = yes
        log file = /var/log/samba/log.%m
        syslog = 0
        panic action = /usr/share/samba/panic-action %d
        encrypt passwords = true
        passdb backend = tdbsam
        obey pam restrictions = yes
        load printers = yes
        printing = cups
        socket options = TCP_NODELAY
        idmap uid = 10000-20000
        idmap gid = 10000-20000
        template shell = /bin/bash
        winbind offline logon = yes
        winbind refresh tickets = yes
        netbios name = TIVFS01
        template homedir = X/%D/%U
        printcap name = cups
        max log size = 4000
        workgroup = X
        security = ads
        realm = X

There's nothing notable in the log files.

Any ideas?