If you used nvidia's installer for the 6106 driver, you will need to re-run the installer after the new xorg-x11 update.
After the xorg-x11 update, glxgears dropped from ~5200 fps to 1750 fps. Re-running nvidia's installer patched things up again.
This is because nvidia's installer effectively replaces some GL libraries with nvidia's accellerated version. The xorg-x11 update re-installs the un-accellerated GL libraries. [My explanation is approximate. So is my understanding. ;) ]
I wish there was some rpm-savvy way for nvidia's installer to handle this situation.]
--Jack