gnome-screensaver doesn't show dialog box to unlock screen

[fdondon]

Binary package hint: gnome-screensaver

After a log period of inactivity, gnome-screen-saver doesn't show the dialog box to unlock the screen.
I was obliged to kill the screensaver process to access the desktop.

Some piece of information :

* computer : Dell Vostro 1710

* lsb_release -rd result
Description: Ubuntu 8.10
Release: 8.10

I've installed the amd64 version

* apt-cache policy gnome-screensaver result
gnome-screensaver:
  Installé : 2.24.0-0ubuntu2
  Candidat : 2.24.0-0ubuntu2
 Table de version :
 *** 2.24.0-0ubuntu2 0
        500 http://fr.archive.ubuntu.com intrepid/main Packages
        100 /var/lib/dpkg/status

ProblemType: Crash
Architecture: amd64
CrashCounter: 1
DistroRelease: Ubuntu 8.10
ExecutablePath: /usr/lib/gnome-screensaver/gnome-screensaver-dialog
NonfreeKernelModules: wl nvidia
Package: gnome-screensaver 2.24.0-0ubuntu2
ProcAttrCurrent: unconfined
ProcCmdline: /usr/lib/gnome-screensaver/gnome-screensaver-dialog --away-message= --enable-switch
ProcEnviron:
 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/lib/gnome-screensaver/gnome-screensaver:/usr/lib/xscreensaver:/usr/lib/xscreensaver
 LANG=fr_FR.UTF-8
 SHELL=/bin/bash
Signal: 11
SourcePackage: gnome-screensaver
StacktraceTop:
 ?? () from /usr/lib/libgnomekbdui.so.3
 ?? () from /usr/lib/libgnomekbdui.so.3
 g_type_create_instance ()
 ?? () from /usr/lib/libgobject-2.0.so.0
 g_object_newv () from /usr/lib/libgobject-2.0.so.0
Title: gnome-screensaver-dialog crashed with SIGSEGV in g_type_create_instance()
Uname: Linux 2.6.27-7-generic x86_64
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare