I never use the GUI to config stuff, but I decided to write a quick script that should help you out.
created the following script should do the trick:
find /etc -print | while read a
if [ ! -d $a ]
ls -l $a
# mod-times.sh >files1.txt
(Go make your changes to your system)
# mod-times.sh >files2.txt
Now diff the two files and you should see the files that got changed. Note that this will not work if you make changes in less than a minute from the time of the first run and the second.
# diff files1.txt files2.txt