Comment 10 for bug 504343

Update:
We've had a nice trace concerning cron.
$ps -ef | grep cron
root 1074 1 0 Feb05 ? 00:00:00 cron
1000 13514 1771 0 21:11 pts/0 00:00:00 grep --color=auto cron

$grep cron /var/log/syslog
Feb 5 17:39:37 host anacron[1394]: Job `cron.daily' terminated (mailing output)
Feb 5 17:39:37 host anacron[1394]: Can't find sendmail at /usr/sbin/sendmail, not mailing output
Feb 5 17:39:37 host anacron[1394]: Job `cron.weekly' started
Feb 5 17:39:38 host anacron[2241]: Updated timestamp for job `cron.weekly' to 2010-02-05
Feb 5 17:40:26 host anacron[1394]: Job `cron.weekly' terminated
Feb 5 17:44:29 host anacron[1394]: Job `cron.monthly' started
Feb 5 17:44:30 host anacron[2389]: Updated timestamp for job `cron.monthly' to 2010-02-05
Feb 5 17:44:30 host anacron[1394]: Job `cron.monthly' terminated
Feb 5 17:44:30 host anacron[1394]: Normal exit (3 jobs run)
Feb 5 18:17:01 host CRON[3309]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Feb 5 19:17:01 host CRON[4875]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Feb 5 20:17:01 host CRON[6380]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Feb 5 21:17:01 host CRON[7900]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Feb 5 22:17:01 host CRON[9414]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Feb 5 23:17:01 host CRON[10959]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Feb 5 23:39:18 host anacron[11670]: Anacron 2.3 started on 2010-02-05
Feb 5 23:39:18 host anacron[11670]: Normal exit (0 jobs run)
Feb 6 16:02:29 host anacron[11758]: Anacron 2.3 started on 2010-02-06
Feb 6 16:02:29 host anacron[11758]: Will run job `cron.daily' in 5 min.
Feb 6 16:02:29 host anacron[11758]: Jobs will be executed sequentially
Feb 6 16:02:44 host init: anacron main process (11758) killed by TERM signal
Feb 6 16:17:02 host CRON[12308]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Feb 6 17:17:01 host CRON[13878]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Feb 6 18:17:01 host CRON[15401]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Feb 6 19:17:01 host CRON[16908]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Feb 6 20:17:01 host CRON[18454]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Feb 6 21:17:01 host CRON[20076]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Feb 6 22:17:01 host CRON[21566]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Feb 6 23:17:01 host CRON[23080]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Feb 7 00:17:01 host CRON[24615]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Feb 7 01:17:01 host CRON[26199]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Feb 7 02:04:18 host anacron[27499]: Anacron 2.3 started on 2010-02-07
Feb 7 02:04:18 host anacron[27499]: Will run job `cron.daily' in 5 min.
Feb 7 02:04:18 host anacron[27499]: Jobs will be executed sequentially
Feb 7 02:04:19 host init: anacron main process (27499) killed by TERM signal
Feb 7 09:40:09 host anacron[27587]: Anacron 2.3 started on 2010-02-07
Feb 7 09:40:10 host anacron[27587]: Will run job `cron.daily' in 5 min.
Feb 7 09:40:10 host anacron[27587]: Jobs will be executed sequentially
Feb 7 09:40:32 host init: anacron main process (27587) killed by TERM signal
Feb 7 10:17:01 host CRON[28988]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Feb 7 11:17:01 host CRON[30697]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Feb 7 12:17:01 host CRON[32166]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Feb 7 13:17:01 host CRON[1261]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Feb 7 14:17:01 host CRON[2838]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Feb 7 15:17:01 host CRON[4346]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Feb 7 16:17:01 host CRON[5927]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Feb 7 17:17:01 host CRON[7464]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Feb 7 18:17:01 host CRON[9004]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Feb 7 19:17:01 host CRON[10600]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Feb 7 20:17:01 host CRON[12130]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Feb 7 21:17:01 host CRON[13667]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)

ls -l /etc/cron.daily/
insgesamt 56
-rwxr-xr-x 1 root root 311 2009-09-17 21:33 0anacron
-rwxr-xr-x 1 root root 189 2009-09-25 23:58 apport
-rwxr-xr-x 1 root root 16338 2009-10-15 21:27 apt
-rwxr-xr-x 1 root root 314 2009-09-28 15:08 aptitude
-rwxr-xr-x 1 root root 502 2009-05-09 01:53 bsdmainutils
-rwxr-xr-x 1 root root 256 2009-09-20 10:24 dpkg
-rwxr-xr-x 1 root root 89 2009-08-20 06:51 logrotate
-rwxr-xr-x 1 root root 1270 2009-09-07 12:19 man-db
-rwxr-xr-x 1 root root 665 2009-04-29 10:35 mlocate
-rwxr-xr-x 1 root root 2149 2009-06-16 15:12 popularity-contest
-rwxr-xr-x 1 root root 3349 2009-09-16 00:32 standard

$ls -l /etc/apt/apt.conf.d/
insgesamt 44
-rw-r--r-- 1 root root 40 2009-10-02 13:07 00trustcdrom
-rw-r--r-- 1 root root 305 2009-09-28 11:30 01autoremove
-rw-r--r-- 1 root root 9 2009-09-28 11:30 01ubuntu
-rw-r--r-- 1 root root 157 2009-09-28 15:08 05aptitude
-rw-r--r-- 1 root root 129 2009-09-10 18:43 10periodic
-rw-r--r-- 1 root root 108 2009-09-10 18:43 15update-stamp
-rw-r--r-- 1 root root 85 2009-09-10 18:43 20archive
-rw-r--r-- 1 root root 235 2009-09-22 12:09 20dbus
-rw-r--r-- 1 root root 765 2009-07-20 13:47 50unattended-upgrades
-rw-r--r-- 1 root root 182 2009-07-07 14:05 70debconf
-rw-r--r-- 1 root root 229 2009-09-10 18:43 99update-notifier

$grep daily /etc/crontab
25 6 * * * root test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.daily )