Hello all,
I've been working on this issue for many hours now and have not been able to obtain a satisfactory result. I am hoping to gain some new insight and perspective in solving this problem.

I recently purchased a Powercolor x1950 Pro Agp from Newegg. This card was meant to replace my old GeForce 6800 XT. I uninstalled the Nvidia driver, then installed the latest Catalyst driver from the ATI/AMD website. Everything ran smoothly until windows started up, which was when I observed very slow refresh lines--slower than those when no driver is installed. After about 20-30 seconds, my monitor would go black and the desktop would show itself again, except a lot of the icons would be missing. Opening the Start Menu would result in the same thing--text would still be there, but the icons would appear and disappear depending on where my mouse was. I decided to attempt a system restart, but this time the display would lock into a resolution of 640x400 @ 4 bit color, and attempts to change the resolution were fruitless.

After two full wipes of my hard drive, setting the AGP bus down to 4x, turning off fastwrites, uninstalling the official Catalyst 7.2 driver and installing Omega 7.1, I've managed to achieve a stable, although probably slowed, system. Updating BIOS, monitor, and motherboard chipset drivers didn't resolve the issue. I'm currently sticking with the Omega 7.1 drivers because it's the set that works best under the circumstances. Any idea what might be going on?

My system specs:
CPU: AMD Athlon 64 3200+
Memory: 1.5 GB DDR 400 RAM
Mobo: Gigabyte GA-K8U socket 754
Graphics: Powercolor x1950 pro agp
PSU: Some server class brand, 450W, +12V 30A

Any help is greatly appreciated. Thanks.

Have you applied all the current MS Updates, including the .NET Framework updates?

I've applied all updates from the Windows Update site and have .NET framework 3.0 installed. Tried reinstalling the display the driver from the CD and obtained the same results.

When uninstalling the Catalyst driver, an error message showed up. Here's what it said:
RUNDLL:
An exception occurred while trying to run "C:/WINDOWS/system32.atiiiexx.dll,_InfEngUninstallINFFile_RunDLL@16 -flags:0x2010001 -inf_classISPLAY -clean -silent"

Interpretation?

Download Driver Cleaner Pro and get rid of the total ATI 7.2 driver. After you have done this, try and reinstall the driver...

You can get Driver Cleaner here:

http://www.softpedia.com/get/Tweak/Uninstallers/Driver-Cleaner-Professional.shtml

You may have some leftover files from the nVidia driver still left, and that may cause some problems. I would download Driver Cleaner Pro, from the link below, then restart in safe mode, and uninstall your ATi drivers again. Then in Driver Cleaner Pro, (after restart) again in safe mode, first run the Cab Cleaner, it will take a while and you may think nothing is happening, be patient. Then, run Driver Cleaner for BOTH nVidia and ATi, restart and reinstall you ATi drivers. Try this and see if it helps.

http://www.softpedia.com/get/Tweak/Uninstallers/Driver-Cleaner-Professional.shtml

Edit: Tmagic 650, you beat me to it. Must be good advice though.

Thanks for the assistance olefarte,
it's always nice to have reinforcement

All right, gave the suggestions a shot. Uninstalled the driver, restarted, cleaned cab files and all ATI/Nvidia related drivers with Driver Cleaner Pro, restarted, and same thing happened again.

Looking around, I found a driver more specific to my pro version. I downloaded and installed this:
https://support.ati.com/ics/support/...estionID=23582

After installing and keeping the AGP speed at 4x, everything ran fine. However, whenever I tried turning it up to 8x, the original problems would repeat again. Here's a link to a screenshot that I took that shows the missing icons, etc:
http://i178.photobucket.com/albums/w262/Unclewang224/DisplayError.jpg

My friend also suggested that the problem could have originated from my Uli chipset, despite having fully updated all the drivers. Could this also be part of the problem?

Thanks in advance.

"My friend also suggested that the problem could have originated from my Uli chipset, despite having fully updated all the drivers. Could this also be part of the problem?"

Yes UncleWang224,
this could be part of the problem. You could upgrade you motherboard, to something a little more proven

Thanks for the help guys. My friend happens to have a spare mobo that I can swap out with; hopefully it will work. Again, thanks for looking at my issue.