original and installed package differ in files

Binary package hint: findutils

while searching for reasons why updatedb slow-downs my laptop very often I found some strange configuration:

there are to jobs in /etc/cron.daily:
"find" which calls "updatedb" and
"mlocate" which calls /usr/bin/updatedb.mlocate

but actually these two scripts call the same binary:

$ ls -l /usr/bin/updatedb
lrwxrwxrwx 1 root root /usr/bin/updatedb -> /etc/alternatives/updatedb
$ ls -l /etc/alternatives/updatedb
lrwxrwxrwx 1 root root /etc/alternatives/updatedb -> /usr/bin/updatedb.mlocate

thus, I checked the package ownership of these scripts

$ dpkg -S cron.daily/find
findutils: /etc/cron.daily/find

and found out that the original package according to http://packages.ubuntu.com/jaunty/i386/findutils/filelist does not list this cron job script.

how could that happen?

using:
Ubuntu 9.04 with resent updates
findutils: 4.4.0-2ubuntu4
mlocate: 0.21.1-1ubuntu1