locale_to_utf8 crashes on WinXP with Gtkmm 2.8.4 / Glibmm 2.8.6 and Gtk+ 2.8.18 / Glib 2.10.3

[Vinzenz 'evilissimo' Feenstra <mailinglist evilissimo-softdev de>]

Hi,

I'm trying to use a string with german umlauts in an application and 
Glib::locale_to_utf8 returns an invalid string.
If I execute this:

Glib::ustring test = Glib::locale_to_utf8("äöüß");

and I retrieve an  invalid object Glib::ustring the debugger shows me an 
Bad Pointer in this object.

I'm wondering if this _can_ be a Glibmm problem or if it is more a Glib 
problem?

Btw anyone knows another GTK+ package like this one from gladewin32.sf.net?

BR

Vinzenz