apcupsd is not launched

Binary package hint: apcupsd

OS: Kubuntu 10.04

$ dpkg -l apcupsd
...
+++-========-================-=================================
ii apcupsd 3.14.6-3ubuntu1 APC UPS Power Management (daemon)

syslog:

kernel [ 3.519531] generic-usb 0003:051D:0002.0002: hiddev96,hidraw1: USB HID v1.10 Device [American Power Conversion Back-UPS RS 500 FW:30.j4.I USB FW:j4] on usb-0000:00:07.2-2.4/input0
kernel [ 3.519617] usbcore: registered new interface driver usbhid
kernel [ 3.519625] usbhid: v2.6:USB HID core driver
...
apcupsd[866] Terminating due to configuration file errors.
apcupsd[866] Lock file read error. ERR=Is a directory
apcupsd[866] apcupsd error shutdown completed

/etc/apcupsd/apcupsd.conf:

/usr/share/doc/apcupsd/examples/usb.conf was took as a basis
for this configuration file where line for DEVICE was
commented out in accordance with APCUPSD User Manual
(section Checking Your Configuration File) which says:
"If you have a USB device, it is better not to specify
a DEVICE directive by leaving it black or commenting it out."
(spelling left untouched).
The line for LOCKFILE was left untouched:
LOCKFILE /var/lock