[gtkmm] signal_key_press_event() question

[Marco <schwein chello nl>]

I want to catch a keypress of enter and turn it into a tab (to go to the 
next entry) to enable the user to quickly enter lots of numbers with the 
numerical keypad.

Then i tried this code to catch a keypress in a Gtk::Entry, but this only 
works with non-printable keys (tab, function keys etc.)
So i think that all printable characters get processed by the entry's 
on_key_press_event() and never make it to OnKeyPress() ?.

class NumberEntry : public Gtk::Entry
{	public:
		NumberEntry();
		 ~NumberEntry();
		bool OnKeyPress(GdkEventKey* event);
};

NumberEntry::NumberEntry()
{	signal_key_press_event().connect(sigc::mem_fun(*this, 
&NumberEntry::OnKeyPress));
}

bool NumberEntry::OnKeyPress(GdkEventKey* event)
{	cout << "Pressed " << event->hardware_keycode << endl;
	return false;
}


I also tried overriding the on_key_press_event() function and was able to 
turn an enter into a tab, however no printable characters made it into the 
entry box.

bool NumberEntry::on_key_press_event(GdkEventKey* event)
{	cout << "Pressed " << event->hardware_keycode << endl;
	//36 = enter, 108 = keypad enter, 13 = tab
	if (event->hardware_keycode==36 || event->hardware_keycode==108)
	{	event->hardware_keycode = 23;
		return on_key_press_event(event); //tab to next
	}
	return false;
}

i'm kinda stuck now, what am i doing wrong?, or is there maybe a much 
simpler way to achieve what i want?

thanks for any help,
Marco