xfdesktop crashed with SIGSEGV in pthread_mutex_unlock()

Binary package hint: xfdesktop4

I've done :

apt-get install xfce4

Installation successfully, nthe next restart I've choose Xfce4 as session and this is the result :)

ProblemType: Crash
Architecture: i386
Date: Sun Jul 8 15:58:54 2007
DistroRelease: Ubuntu 7.10
ExecutablePath: /usr/bin/xfdesktop
NonfreeKernelModules: cdrom
Package: xfdesktop4 4.4.1-4ubuntu1
PackageArchitecture: i386
ProcCmdline: xfdesktop
ProcCwd: /home/luca
ProcEnviron:
 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games
 LANG=it_IT.UTF-8
 SHELL=/bin/bash
Signal: 11
SourcePackage: xfdesktop4
StacktraceTop:
 ?? () from /lib/tls/i686/cmov/libc.so.6
 ?? ()
 ?? ()
 ?? ()
 pthread_mutex_unlock ()
Title: xfdesktop crashed with SIGSEGV in pthread_mutex_unlock()
Uname: Linux Desktopuntu 2.6.22-7-generic #1 SMP Mon Jun 25 17:33:14 GMT 2007 i686 GNU/Linux
UserGroups: adm admin audio cdrom dialout dip floppy lpadmin netdev plugdev powerdev scanner video
SegvAnalysis:
 Segfault happened at: 0xb74f2d10 <_fini+632828>: mov 0x4(%esi),%eax
 PC (0xb74f2d10) ok
 source "0x4(%esi)" (0x00000005) not located in a known VMA region (needed readable region)!
 destination "%eax" ok
SegvReason: reading NULL VMA