Glib::ustring::format throws exception

[Yggi Rebuet <yggi hotmail com>]

Hello.
The following code throws an exception:

#include

int main(int argc, char* argv[])
{
    Gtk::Main MainObj(argc, argv);
    int i = 1;
    const Glib::ustring label = Glib::ustring::format(i);
    //or: const Glib::ustring label = Glib::ustring::compose("%1", i);
    Gtk::Window WindowObj;
    WindowObj.set_title(label);
    MainObj.run(WindowObj);
    return 0;
}

The Debugger marks the line "return buf.to_string();" here:

template
inline // static
ustring ustring::format(const T1& a1)
{
  ustring::FormatStream buf;
  buf.stream(a1);
  return buf.to_string();
}

I get an Error from Glib::ConvertError.

I'm using Windows 7 64bit with MSVC10 and Gtkmm 2.4 32 (Binary Package was used).
However everything works great except this conversion problem.