Thanks everyone for the input and for confirming this is caused by the nvidia driver.
Those who still experience the bug with nvidia-319.xx (which reportedly should work) could you please try nouveau to make sure it's not yet another issue in the binary drivers? If you can reproduce the problem with nouveau, please open a new bug report. We will use this one to track only the nvidia-related issue. I'll close this as UPSTREAM, since we can't do anything about it. As recommended in comments above, either wait for nvidia to release an update, downgrade to nvdia-319.xx or switch to the open source nouveau driver. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to akonadi in Ubuntu. https://bugs.launchpad.net/bugs/1245979 Title: After Upgrade to Kubuntu 13.10 akondai fails to register at d-bus session, making kde-pim suit unusable Status in Akonadi - The PIM Storage Service: Won't Fix Status in “akonadi” package in Ubuntu: Confirmed Bug description: Upon opening Kontact akonadi is supposed to be loaded but fails with the following error: Akonadi fails to register at d-bus session. I safed the self-test protocoll of the akonadi server and attached the report. I already deleted all my akonadi config files but it did not resolve the error. To manage notifications about this bug go to: https://bugs.launchpad.net/akonadi/+bug/1245979/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp