regression: no dock or menu bar after login

[Barry Warsaw]

After today's round of updates, rebooting and re-logging in with Unity 2d desktop, I get no side dock or menu bar on either screen of my dual-headed system. I do see the one folder in my ~/Desktop and right click on the background does bring up a menu. Since I have Gnome Do installed, I am able to bring up a terminal and interact with its title bar. Maximizing the window works but there is no global menu.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: unity-2d 5.4.0-0ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-17.27-generic 3.2.6
Uname: Linux 3.2.0-17-generic x86_64
ApportVersion: 1.93-0ubuntu2
Architecture: amd64
Date: Fri Mar 2 10:00:22 2012
EcryptfsInUse: Yes
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Alpha amd64 (20110705.1)
PackageArchitecture: all
SourcePackage: unity-2d
UpgradeStatus: Upgraded to precise on 2012-02-27 (3 days ago)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Steve Langasek (vorlon)]

marked 'critical' since this will render the desktop unusable for anyone on hardware requiring the 2d fallback.

[Ed Mountjoy (emountjoy-deactivatedaccount)]

I had this problem with Unity-2D yesterday but it seems to be working today.

[Espen Meidell (espen-meidell)]

I have the same problem, except for that i have global menus.

[Nicolas VILA (nicolas-vila)]

There are many regression in the 5.x version of unity-2d.
1) No global menu anymore in Unity2D, wich was working in 11.10 (unity4) with same hardware
2) No way to enable auto-hide of the dock panel (always show is the only viable option for me, when selecting other option there is no panel at all)
3) I'm using old hardware with nvidia-173 drivers and I don't like the fact "composite" is mandatory to use Unity correctly (very laggy) I had to force composite to "off" to avoid laggy windows by modifying /etc/X11/xorg.conf:

Section "Extensions"
    Option "Composite" "Disable"
EndSection

Notes:
Not directly related with Unity but nvidia-173 drivers are not compatible with Xorg version released in 12.04. So I stick with 11.10 version of Xorg. I had to make the following changes to backport Xorg:

In /etc/apt/sources.list :

Package: xserver-xorg*
Pin: release a=oneiric
Pin-Priority: 1050

In /etc/apt/preferences:

deb http://fr.archive.ubuntu.com/ubuntu/ oneiric main
deb-src http://fr.archive.ubuntu.com/ubuntu/ oneiric main