website link in Gtk::AboutDialog

[Sergio Perticone <g4ll0ws gmail com>]

Notice: not important issue, just curiosity.

I've read the example in <src_root>/examples/book/dialogs/aboutdialog/ 
but I can't create the website clickable label (something such as in eog 
about dialog).
set_website_label() doesn't seems work and my url is displayed just like 
a normal label.

I tried to do that with GTK+ (inside my gtkmm app and in a separate C 
test) but the song remains the same...
What should I do?

ps. Yep, I've seen eog source related to that, it's the same of mine.
pps. I'm using gtkmm-2.10.8