QDbus fails to start on login

[[Po]lentino]

Today I freshly-installed Kubuntu Thrusty Thar Beta2 downloaded from here: http://cdimage.ubuntu.com/kubuntu/releases/trusty/beta-2/ .
After the installation, I rebooted the laptop and i successfully logged into KDE. After a while, the package manager notified me about new pakage updates, so I installed them and rebooted again ... and now I cant' login into KDE anymore.
When I try log in, a small window pops up instead and tells me :

"Could not start dbus. Can you call DBus?"

Weird.
So I typed CTRL+ALT+F1, logged in tty1, and invoked qdbus. Here's what I got:

"Could not connect to D-Bus server: org.freedesktop.DBus.Error.NotSupported: Unable to autolaunch a dbus-daemon without a $DISPLAY for X11"

What's going on here?
Cheers,

Diego.

[lordievader (oliviervdtoorn)]

Isn't this a duplicate of Bug #1304805

[[Po]lentino (polentino911)]

Oh right, mine's a little bit detailed but yep, it's duplicated ;)

[Launchpad Janitor (janitor)]

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