update-gnome-menus-cache crashed with Error in setlocale()

Binary package hint: gnome-menus

This error was thrown during a dist-upgrade. since the error message contains the word "locale" I will paste the output of locale:

yelo3@yelo3-laptop:~$ locale
locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannot set LC_ALL to default locale: No such file or directory
LANG=en_US.UTF-8
LC_CTYPE=it_IT.UTF-8
LC_NUMERIC=it_IT.UTF-8
LC_TIME=it_IT.UTF-8
LC_COLLATE=it_IT.UTF-8
LC_MONETARY=it_IT.UTF-8
LC_MESSAGES="en_US.UTF-8"
LC_PAPER=it_IT.UTF-8
LC_NAME=it_IT.UTF-8
LC_ADDRESS=it_IT.UTF-8
LC_TELEPHONE=it_IT.UTF-8
LC_MEASUREMENT=it_IT.UTF-8
LC_IDENTIFICATION=it_IT.UTF-8
LC_ALL=

ProblemType: Crash
Architecture: amd64
Date: Wed Jan 6 22:00:53 2010
DistroRelease: Ubuntu 10.04
ExecutablePath: /usr/bin/update-gnome-menus-cache
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release amd64 (20091027)
InterpreterPath: /usr/bin/python2.6
Package: python-gmenu 2.28.0.1-0ubuntu6
ProcCmdline: /usr/bin/python /usr/bin/update-gnome-menus-cache /usr/share/applications
ProcVersionSignature: Ubuntu 2.6.32-9.13-generic
PythonArgs: ['/usr/bin/update-gnome-menus-cache', '/usr/share/applications']
SourcePackage: gnome-menus
Tags: lucid
Title: update-gnome-menus-cache crashed with Error in setlocale()
Uname: Linux 2.6.32-9-generic x86_64
UserGroups: