Logcheck users - Feb 2008 - Logcheck running multiple times over the course of an hour

I  use logcheck 1.2.42 on Ubuntu 6.06 LTS. It used to work perfectly, however
recently it has been
running multiple times. I use the default cron job to run it -
/etc/cron.d/logcheck looks like
this:

# /etc/cron.d/logcheck: crontab entries for the logcheck package

PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/us r/sbin:/usr/bin
MAILTO=root

@reboot logcheck if [ -x /usr/sbin/logcheck ]; then nice -n10 /usr/sbin/logcheck
-R; fi
* 2 * * * logcheck if [ -x /usr/sbin/logcheck ]; then nice -n10
/usr/sbin/logcheck; fi

# EOF

At 2am it runs correctly, however it then continues to run every couple of
minutes for the next
hour, so that I get about 26 logcheck emails sent between 2 & 3 am. The
first email always says it
can't get a lock on the lockfile, the next includes all the info from the
previous day then the
remainder all contain info from the couple of minutes between them & the
previous email. Any ideas
why it's doing this - there's no entry in the root crontab, nor in
/etc/cron.daily, so I can't see
why it's running continuously. At reboot it runs fine - just once.