On closer inspection, it seems that the feature you are trying to use is a
Kubuntu-specific feature, requiring this package that has not been rebuilt
for Ubuntu Intrepid or later:
http://packages.ubuntu.com/hardy/language-selector-qt

I am seriously considering removing the buttons labeled "Install New
Language", "Uninstall Language", and "Select System Language" from the
official Trinity distribution.  These buttons can be added later via a
patch for Kubuntu-specific builds, after the package mentioned above has
been successfully built under Maverick.

As such I request that you open a bug at http://bugs.pearsoncomputing.net
as a feature request for the language selector buttons under Kubuntu.

Thanks!

Tim

> Yes.
> ksenz@tux:~$ dpkg --get-selections | grep kdesudo
> kdesudo install
> kdesudo-kde3 install
>
>
> 2010/9/12 Timothy Pearson <kb9vqf@...>
>
>> Did you install kdesudo or kdesudo-kde3?
>>
>> > sudo-kde3 and kdesudo already installed... but the problem remains
>> >
>> > 2010/9/10 Timothy Pearson <kb9vqf@...>
>> >
>> >> > Hello!
>> >> > When I push the button "Install new language" in the "Regional &
>> >> Language"
>> >> > settings, I get window "Error - KdeSudo Command not found"
>> >> >
>> >> > Also, I can not turn the "Administrator mode ..." because not
>> >> installed
>> >> > package libpythonize0-kde3
>> >> >
>> >>
>> >> Install sudo-kde3 and kdesudo will start working again.
>> >>
>> >> Tim
>> >>
>> >>
>> >
>>
>>
>>
>