Tons of DBUS error and apps unavailability

[Ambrogio De Lorenzo]

Hi all,
I see a lot of DBUS error in the messages:

 dbus[11185]: [system] Failed to activate service 'org.freedesktop.systemd1': timed out
 dbus-daemon: dbus[11185]: [system] Failed to activate service 'org.freedesktop.systemd1': timed out
 dbus[11185]: [system] Activating systemd to hand-off: service name='org.freedesktop.hostname1' unit='dbus-org.freedesktop.hostname1.service'
 dbus-daemon: dbus[11185]: [system] Activating systemd to hand-off: service name='org.freedesktop.hostname1' unit='dbus-org.freedesktop.hostname1.service'
 dbus[11185]: [system] Failed to activate service 'org.freedesktop.hostname1': timed out
 dbus-daemon: dbus[11185]: [system] Failed to activate service 'org.freedesktop.hostname1': timed out
 dbus[11185]: [system] Failed to activate service 'org.freedesktop.systemd1': timed out
 dbus-daemon: dbus[11185]: [system] Failed to activate service 'org.freedesktop.systemd1': timed out

I use KDE and the errors are frequent when an application have to open
the file selector windows (Libreoffice on save as or Virtualbox in
select a disk).
The timeout is about 2 3 minutes.
I can't understand why (but I think this is also related to a NFS
filesystem mounted on my machine - I have to test without it).
Little timeout I have also when I unlock the session.
A big timeout when I logoff and logon with the same user.

I can't found solutions.
There is someone that had the same problem?

Bye
 Ambrogio