HardwareHeaven.com - Drivercleaner kills ATI OpenGL ICD

Hi all,
I'm getting some strange behavior when cleaning out my ATI drivers... it got rid of a registry setting that for some reason DIDN'T get restored when I reinstalled the new set of drivers (in this case Omega 6.5).

At first I didn't notice that opengl didn't work anymore because I didn't try any apps that used it for a few weeks. It took me a whole day of trying to track down what exactly happened, but I still don't know why subsequent installs of new drivers did not re-add the entry. Somehow it got locked?? The entry in question is at:
...
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\OpenGLDrivers\]

and the entry "ati2dvag" was removed. To fix it, I actually had to re-add it manually, with "Dll"="atioglxx.dll" and a couple of other entries. Otherwise, it would just use the generic GDI software opengl.

My questions: how do I unlock registry entries, so that future installs will go smoothly? Could there be other registry entries that aren't being reset properly? It is doubtfull that it's the Omega drivers, because the same thing happened with the official Catalysts. I tried 6.1, 6.2, 6.3 and they all failed to add the registry entry.

DirectX has been working fine a usual through all of this. Could this be a drivercleaner bug or what?

my specs:
ECS L7S7A2 w/ AMD 2700+
ATI Radeon 9800pro, original Audigy card.
Omega drivers based on Catalyst 6.5