Problems with making Notebook tabs dragable (as in DnD-dragable)

[Martin Nordholts <enselic gmail com>]

Hello,

I am implementing Drag and Dropable Palettes (Dialogs in GIMP-speech) as
in GIMP. For this I have a class PaletteNotebok : public Gtk::Notebook.

Whenever a page is added, I want the class to automatically fix DnD
support for the Page Tab Label.

However, I am unable to do this on a notebook. This is a simple
testcase:
http://rafb.net/p/GzChRZ36.html
and it causes a segfault on line 57.

I have tried to find anything through valgrind and gdb, but that gives
me nothing.

When I "convert" the code in the example to use DnD on normal Buttons
instead of notebook tab labels, it works fine.

Is this a bug in gtkmm, or am I doing something wrong?

Thank you,
- Martin N.