Cannot display "Monitor & Display" kcontrol module; Python exception

Binary package hint: kde-guidance

I get the following exception when trying to view the "Monitor & Display" module in kcontrol:

Traceback (most recent call last):
  File "<string>", line 8, in kcontrol_bridge_create_displayconfig
  File "/var/lib/python-support/python2.4/displayconfig.py", line 1687, in create_displayconfig
    return DisplayApp(parent, name)
  File "/var/lib/python-support/python2.4/displayconfig.py", line 443, in __init__
    self.xsetup = XSetup(self.xconfigpath)
  File "/var/lib/python-support/python2.4/displayconfigabstraction.py", line 73, in __init__
    self.xorg_config = xorgconfig.readConfig(xorg_config_filename)
  File "/var/lib/python-support/python2.4/xorgconfig.py", line 641, in readConfig
    for row in XorgconfCVSReader(filename=filename).readlines():
  File "/var/lib/python-support/python2.4/xorgconfig.py", line 696, in __init__
    fhandle = codecs.open(filename,'r',locale.getpreferredencoding(),'replace')
  File "/usr/lib/python2.4/locale.py", line 417, in getpreferredencoding
    setlocale(LC_CTYPE, "")
  File "/usr/lib/python2.4/locale.py", line 381, in setlocale
    return _setlocale(category, locale)
locale.Error: unsupported locale setting
error: *** runFunction failure
;

This does not happen, if I start kcontrol with the "C" locale.
LANG=C kcontrol

LANG is "de_DE.UTF-8" here.

The problem is probably not with kde-guidance itself, but a package it relies on, so please change it accordingly.