Comment 108 for bug 728745

I found a fix, at least for my system, in the Debian User Forums:

http://forums.debian.net/viewtopic.php?f=7&t=65539 "Lost 3D after updating nvidia-glx, linux and X".

Someone advised installing/updating the following packages:

libegl1-mesa_7.10.2-3_i386.deb
libglu1-mesa_7.10.2-3_i386.deb
libegl1-mesa-drivers_7.10.2-3_i386.deb
xserver-xephyr_1.10.2-1_i386.deb
libgl1-mesa-dri_7.10.2-3_i386.deb
xserver-xorg-core_1.10.2-1_i386.deb
libgl1-mesa-glx_7.10.2-3_i386.deb

I (re)installed the Ubuntu amd64 equivalents:

libegl1-mesa
libglu1-mesa
libegl1-mesa-driver
xserver-xephyr
libgl1-mesa-dri
xserver-xorg-core
libgl1-mesa-glx

Two of these packages, libegl1-mesa and libegl1-mesa-driver, WERE NOT installed on my system after the upgrade to natty. I don't know why they weren't installed during the upgrade, or if they were there before the upgrade. They seem to be needed.

After banging in these packages, the Unity Desktop Environment works as well as can be expected. (Snarky comments removed.) Of course, I am running the nVidia 275.09.07 drivers instead of the ones in the Ubuntu repository...

A great Father's Day present for me! Happy Father's Day to all the dads out there.