[Kubuntu7.10]Adjusting Gamma parameter in system->display settings messes up the xorg.conf. Display defaults to lowest resolution on rebooting

Hello

 I had this problem several times and went through the various bug reports.brin
I guess this bug has been reported fixed but then I wish to share my workaround -- will
that help localizing the problem?

System: Acer Aspire 4710N (Intel core2duo 2GB RAM 160 GB HDD etc) Kubuntu 7.10

The LCD screen was too bright and there was no way to reduce the brightness of screen.
So I went and tried reducing the gamma parameter (from 1+ to under 0.5 using the slider button).
Brightness got reduced. My resolution was: 1024 x 768. I saved the changed settings (ie., exited the systemsettings program)

On the next boot of the laptop, the screen resolution defaulted to 640x480. When I looked
up K->system->display settings, the only screen resolution available was 600x480. Even krandrtray would show only option
of 640x480 resolution.

I then looked up /etc/X11/xorg.conf and found the monitor and screen sections changed.
The xorg.conf has been overwritten.

The autogenerated xorg.conf (relevent section) is:
============================
Section "Monitor"
        Identifier "Generic Monitor"
        Vendorname "Plug 'n' Play"
        Modelname "Plug 'n' Play"
  modeline "640x480@60" 25.2 640 656 752 800 480 490 492 525 -vsync -hsync
        Gamma 0.5
EndSection

Section "Screen"
        Identifier "Default Screen"
        Device "Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller"
        Monitor "Generic Monitor"
        Defaultdepth 24
        SubSection "Display"
                Depth 24
                Virtual 640 480
                Modes "640x480@60"
        EndSubSection
EndSection

===================================

Then I had to edit out certain lines and introduce new ones - the operational xorg.conf (relevant sections) is:

===================

Section "Monitor"
        Identifier "Generic Monitor"
        ModeLine "1024x768@60" 65.0 1024 1048 1184 1344 768 771 777 806 -hsync -vsync
        Gamma 0.5
EndSection

Section "Screen"
        Identifier "Default Screen"
        Device "Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller"
        Monitor "Generic Monitor"
        Defaultdepth 24
        SubSection "Display"
                Depth 24
                Modes "1024x768" "640x480@60"
        EndSubSection
EndSection

===================

Initially I used to edit the xorg.conf, restart the x-server. But on login, it used to revert back to the earlier screen
resolution 640x480. Then when I went into k->system-settings->display, then the slider menu (which earlier showed
a single point slider scale of 640x480) would now show a proper slider scale (with current setting at 640x480). Then
I used to move the slider to desired level and apply. I would get the desired screen resolution.

I then found that I had to do this above sequence everytime I booted my laptop - it used to revert back to 640x480.

The workaround I discovered was when I completed the above sequence, exited system-settings., then edited
the xorg.conf to deleted the lines except those below (a guesswork).
=======
Section "Monitor"
        Identifier "Generic Monitor"

        Gamma 0.5
EndSection

Section "Screen"
        Identifier "Default Screen"
        Device "Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller"
        Monitor "Generic Monitor"
        Defaultdepth 24
        SubSection "Display"
                Depth 24
                Modes "640x480@60"
        EndSubSection
EndSection
===========

And then I added:
  ModeLine "1024x768@60" 65.0 1024 1048 1184 1344 768 771 777 806 -hsync -vsync
to the Section "Monitor" the well as 'Modes "1024x768" ' to the Section Screen

 This stabilized the xorg.conf and the resolution problem. Now
when I boot my system it comes up with the right resolution 1024x768.

My questions:
a) Is this a problem with KDE's monitor&display settings utility? why is it flaky?
b) why was so many xorg.confs getting generated (The above was very repeatable).
c) What makes the xorg.conf complete? (My working versions are incomplete but some default
values not in xorg.conf gives me the satisfactory resolution settings). My work seems a perfect hack.
d) what is the way to reduce the brightness of the screen apart from playing with gamma parameter?
e) My expectation - if I play with k->systemsettings->monitor-displaysettings parameters, I should
be able to get back my original settings without xorg.conf getting mauled off from its initial installation version.