DSLocalizator only uses the values from the cultures that come with the dotnet framework installed in your system

There are another questions about similar problems on the DNN forums. It is a bug of the dotnet framework.

To test that you can download the snippet compiler from

http://www.sliver.com/dotnet/SnippetCompiler/

and execute the following code:

<code>

</code>

and you will see that nativename get the "p" using lowercase.