Horizontal line on display with ATI Rage Mobility

I’ve googled for several days in attempt to find solution to this common problem with ATI Rage Mobility cards and I give up. I hope someone more experienced with X.org and graphical drivers can help me resolve this.

First of all, my laptop is Compaq Armada M700. I’m quite sure the problem is in graphics card and not in the monitor because other people with different laptops from different manufacturer have reported the same problem, and they all have ATI Rage Mobility. I have OpenSUSE 10.3 installed.

Problem description:
There is about 1cm (half an inch) horizontal white line on my display when KDE starts, located close to the top of the screen. In addition, the bottom of desktop is located below the screen, so I can’t see my KDE taskbar unless I move it to the top or either side of the desktop. The line doesn’t appear during SUSE installation or while KDE is loading. When I move my mouse pointer over the line it appears one the other side of it, so it can be called a ‘dead zone’.

My attempts at solution:
I tried to solve this with sax2 settings. Found the dimensions of my display on HP support website and entered them in sax2. I also changed my display type setting from VESA to LCD. It didn’t help.

The parts of my xorg.conf that I think are important look like this:

Section “Module”
Load “dbe”
Load “type1”
Load “freetype”
Load “extmod”
Load “glx”

Section “Monitor”
DisplaySize 284 213
HorizSync 29-60
Idnetifier “Monitor[0]”
ModelName “1024X768@60HZ”
Option “DPMS”
VendorName “–> LCD”
VertRefresh 50-60
UseModes “Modes[0]”

Section “Device”
BoardName “3D Rage P/M Mobility AGP 2x”
BusID 1:0:0
Driver “ati”
Identifier “Device[0]”
Option “usevnc” “no”
VendorName “ATI”

Section “DRI”
Group “video”
Mode 0660