Glib::ustring strange error msg ??

[Jamiil <jalqadir gmail com>]

I found a strange error when using Glib::ustring, when using GNU 
debugger I get this message:
=============================
glibmm-ERROR **
unhandle exception(type std::exception) in signal handler;
what: basic_string::_S_C
=============================

Here is the relevant code regarding this error message
======= snip ========
namespace jve {
  enum title_t{Mr,   
               Mrs,   
               Miss,
               ...
              };
== somewhere else
const Glib::ustring& jve::Person::getTitle(){
  switch(title){
     case Mr:   {return "Mr";  }
     case Mrs:  {return "Mrs"; }
     case Miss: {return "Miss";}
     case Ms:   { return "Ms"; }
     case Dr:   { return "Dr"; }
     default:   {return "None";}
  }
}
  
Glib::ustring msg = person->getTitle(); <<=== this causes an 
segmentation fault

I am using WindowsXP and Gtkmm 2.10.x

Is this a bug??
What am I doing wrong?
   
Thanks folks

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