Gnome applications fail to launch under Kubuntu 11.10. FGRLX related problems?

I am using Kubuntu 11.10 x86_64 (German Localization) on an Acer TravelMate 5740G notebook.
When I try to launch the gnome alsa mixer (in lack of a good corresponding KDE application as it seems) it will not start. It appears in the task bar for a few seconds, but apart from that nothing happens. Then the program is terminated again without an error message.
I have had the same problem in Xubuntu 11.10, so it doesnt' seem to be a KDE specific problem.

However, I have had similar problems with other Gnome / GTK programs failing to launch. Both with Kubuntu and Xubuntu. I believe the errors are related to the FGLRX driver. When I installed it on the regular Ubuntu the Unity interface did not work anymore and the system became unusable. The same happened on Fedora 15 with Gnome 3, which I had installed before I switched to Ubuntu. As soon as I installed FGLRX the GUI became destroyed. Apparently there seem to be compatibility issues between FGLRX and Gnome 3 / GTK3 when you have a Mobility Radeon HD 5650 graphics card.

The proprietary drivers tool offers me an update for fglrx (See screenshot! The "nachträgliche Aktualisierung" in brackets means "supplementary update". Note the driver is misspelled "FGRLX" for the update!) but fails to install it. When I try the packages are downloaded but the installation fails with a general error message and fglrx is rendered unfunctional then. It needs to be reinstalled (the regular fgrlx package you can see on the screenshot) to work again.
When I tried to install the driver with the fgrlx-installer directly downloaded from AMD the graphics system did not start anymore at all. So probably the error is in the fgrlx installer.

-- COMMENT -- No screenshot attatched, because rekonq crashed every time I try to do it.

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: gnome-alsamixer (not installed)
ProcVersionSignature: Ubuntu 3.0.0-12.20-generic 3.0.4
Uname: Linux 3.0.0-12-generic x86_64
NonfreeKernelModules: wl fglrx
ApportVersion: 1.23-0ubuntu3
Architecture: amd64
Date: Sat Oct 29 17:07:17 2011
InstallationMedia: Kubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
ProcEnviron:
 LANGUAGE=
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: gnome-alsamixer
UpgradeStatus: No upgrade log present (probably fresh install)