How to make an upgraded system clean by automatically removing abandoned config files?

[Drew Engelbrecht <naturaltwig@gmail.com>]

I've noticed some abandoned configuration files have been left lying around my harddrive, which by their existence have a (sometimes negative) effect on my upgraded system. They were installed by packages in lenny, but would not be installed in a fresh installation of squeeze. Despite unmodified configuration files getting replaced by newer ones when upgrading, it seems that if they don't belong to the same package in squeeze as in lenny, then they are not removed... even though that file may be unmodified from the original (and now useless or even harmful.)

For example, there's the /etc/X11/xorg.conf file that dpkg-reconfigure doesn't change or remove in squeeze (and doesn't add, if there's not one there.)
Also, there was a file in /etc/udev/rules.d/ for wacom input. Something like 50 errors would show up when I booted, because of this file.

I noticed that using the "loate" command for the xserver-xorg-input-wacom package listed the problematic rules file, so my system knew that it was there and associated with the package. I tried purging the wacom package and reinstalling xserver-xorg-input-all. The file and the problem went away. Unfortunately, I don't think that it's feasible to purge and reinstall the entire installation base though ;-) so I'm still looking for a general solution.

Is there a way to remove deprecated files like these automatically? I'm having some minor issues with squeeze, and I can't help but wonder if there are still some "zombie" config files that are creating issues here by making my system less like a clean install of squeeze.

Any help is appreciated.

Thanks,
-Drew