After normal upgrade to 12.04 did not upgrade kde, I manually did the update, upgrade cycle only to be prompted to do an apt-get -f install. Doing that resulted in error notices about xmind having a blank line in its Description. After fixing that, in both pkgs and available, the upgrade cycle completed. The reboot then showed my desktop without wallpaper or my usual programs list, but at least with an applications list I could choose from.
The first reboot after the manual upgrade tried to report a dbus problem which has no coherent google-able useful report. But that did not recur on the second reboot, which then yielded this error.
ProblemType: Package
DistroRelease: Ubuntu 12.04
Package: libatk-adaptor-schemas 2.4.0-1ubuntu2
ProcVersionSignature: Ubuntu 3.2.0-24.37-generic 3.2.14
Uname: Linux 3.2.0-24-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.0.1-0ubuntu6
Architecture: amd64
Date: Thu Apr 26 20:38:40 2012
DuplicateSignature:
Unpacking libatk-adaptor-schemas (from .../libatk-adaptor-schemas_2.4.0-1ubuntu2_amd64.deb) ...
dpkg: error processing /var/cache/apt/archives/libatk-adaptor-schemas_2.4.0-1ubuntu2_amd64.deb (--unpack):
trying to overwrite '/usr/share/glib-2.0/schemas/org.a11y.atspi.gschema.xml', which is also in package libatk-adaptor 2.2.1-0ubuntu1
ErrorMessage: trying to overwrite '/usr/share/glib-2.0/schemas/org.a11y.atspi.gschema.xml', which is also in package libatk-adaptor 2.2.1-0ubuntu1
SourcePackage: at-spi2-atk
Title: package libatk-adaptor-schemas 2.4.0-1ubuntu2 failed to install/upgrade: trying to overwrite '/usr/share/glib-2.0/schemas/org.a11y.atspi.gschema.xml', which is also in package libatk-adaptor 2.2.1-0ubuntu1
UpgradeStatus: Upgraded to precise on 2012-04-26 (0 days ago)
Status changed to 'Confirmed' because the bug affects multiple users.