I was just getting used to it and now it won't work. I had made a pact with
myself (I am prone to making stupid pacts like this) to only use Unity until
the final release came out. Then this past weekend Unity will not work after
an upgrade. I get my desktop with icons, a screen flicker, and then only get
an application panel. It looks like Nautilus but nothing beyond that (no
file manager). Since I have used it enough to know some hot keys I can bring
up terminals and work from there, but that was hardly my intent when I made
the pack to use only Unity. I want the Launcher, dash and top panel. :(

I tried to troubleshoot first by reinstalling Unity and then ubuntu-desktop.
No luck. I then tried Additional Drivers to see if my graphics driver had
changed (Not). Then I looked at Compiz and reinstalled it. :( So finally I
switched to Unity 2D and used it for a bit. Deciding that it was not Unity,
I broke my pact and am in GNOME Shell which is slow on my computer and not
to my taste. Think full screen. Everything. No buttons except X to close. It
has a simple concept. There are Two words on the top panel, Activities on
the left and your user name at the right. The Date and time is in the
middle. There is a volume control, Network and Accessibility icon and that
is it. Every few key presses it freezes (it did since the beginning of this
sentence) and you have to wait ten or so seconds before you can continue. No
repetitive strain here. No GNOME love at this point.

I will break my pact once again and go back to KDE which works perfectly,
BTW, and try to straighten Unity out.

It is not my graphics card ( 1 GB ATI) because it works fine in KDE with
full compositing. It also works in GNOME Shell, Enlightenment, XFCE, etc.
It is not a RAM issue (6 GBs) because in KDE I have 9 Activities and four
virtual desktops on each (36 workspaces) and I can multi-task like no
tomorrow with no slow down.

I will start by re-booting to an older kernel.

If anyone has had a similar problem let me know.