I can't start KDE4 any more - it fails to start dbus. To be more exact, qdbus gives this error message when it is run:
Could not connect to D-Bus server: org.freedesktop.DBus.Error.Spawn.ExecFailed: Failed to execute dbus-launch to autolaunch D-Bus session
But when I run dbus-launch it works fine. I'm sure it's probably something simple, but I'm about ready to give up.