tripwire reports constant changes of /usr/doc and /home

[MaD dUCK <madduck@madduck.net>]

folks,
this one leaves me puzzled, so i was wondering if you could help
me out. every day, tripwire reports to me that on one of my
systems (only), the directories /home and /usr/doc have changed:

changed: drwxr-xr-x root         8192 Aug  6 16:18:56 2001 /usr/doc
changed: drwxr-xr-x root         4096 Jul 27 12:42:46 2001 /home

none of the entries within these directories have changed, nor are
they reported, but these two directories still continue to fill up
my tripwire reports.

at first, it was only /home, and i thought it had anything to do with
the quotae i enabled on that partition, but /usr/doc is (a) not a
partition of its own, and (b) /usr doesn't have quotae.

this is weird, since it happens only on one of my otherwise identitical
systems, and i need to figure out why. where do i start?

thanks,
martin;              (greetings from the heart of the sun.)
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