x server crashes when accessing the screen savers within gnome

Binary package hint: gnome-screensaver

this is what I get, when trying to access from terminal:

process 6758: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3168.
This is normally a bug in some application using the D-Bus library.
process 6758: arguments to dbus_message_iter_init() were incorrect, assertion "message != NULL" failed in file dbus-message.c line 1749.
This is normally a bug in some application using the D-Bus library.
process 6758: dbus message iterator looks uninitialized or corrupted
process 6758: arguments to dbus_message_iter_get_basic() were incorrect, assertion "_dbus_message_iter_check (real)" failed in file dbus-message.c line 1956.
This is normally a bug in some application using the D-Bus library.
process 6758: arguments to dbus_message_unref() were incorrect, assertion "message != NULL" failed in file dbus-message.c line 1391.
This is normally a bug in some application using the D-Bus library.

** (gnome-screensaver:6758): WARNING **: Registrierung am Message-Bus fehlgeschlagen

ProblemType: Bug
Architecture: i386
Date: Fri Mar 30 19:40:36 2007
DistroRelease: Ubuntu 7.04
Uname: Linux kroete 2.6.20-12-generic #2 SMP Wed Mar 21 20:55:46 UTC 2007 i686 GNU/Linux