Re: GLX causes Signal 11
Probably you haven't installed the Nvidia driver correctly. The driver comes with both its own libraries, as well as the X extension. Your X log indicates that you are loading the X provided glx extension -- if the driver is installed properly, it should say something like "vendor=Nvidia" .
Furthermore, the ldd output shows that glxgears is linked with the GLX library provided by X, not the one supplied with the Nvidia driver. The latter should be in /usr/lib/tls (this should be reflected in the ldd output).
Try uninstalling the driver and re-install it from scratch. The README in the driver package provides the exact information regarding GLX, if you follow it everything should be fine.