fail2ban ADVERTENCIA comando no válido en sitios web deshabilitados apache2

Question

Tengo un problema en un servidor web Debian Squeezy que ejecuta fail2ban. De vez en cuando, fail2ban deja de funcionar quejándose de que falta access.log:

fail2ban.comm   : WARNING Invalid command: ['set', 'http-get-dos', 'addlogpath', '/var/www/foo.bar/log/access.log']

Tengo que tocar el archivo infractor y reiniciar fail2ban para comenzar a prohibir nuevamente.

¿Cualquier sugerencia?

[EDITAR] Añadido logrotate.conf

# see "man logrotate" for details
# rotate log files weekly
weekly

# keep 4 weeks worth of backlogs
rotate 4

# create new (empty) log files after rotating old ones
create

# uncomment this if you want your log files compressed
#compress

# packages drop log rotation information into this directory
include /etc/logrotate.d

# no packages own wtmp, or btmp -- we'll rotate them here
/var/log/wtmp {
    missingok
    monthly
    create 0664 root utmp
    rotate 1
}

/var/log/btmp {
    missingok
    monthly
    create 0660 root utmp
    rotate 1
}

# system-specific logs may be configured here