Happened to me recently as well; here's my thread about it.
http://www.triumphrat.net/triumph-su...-cylinder.html
I ended up with an aprilia switch...its the same switch, but the switch screw holes don't quite line up properly.
Curious; what other 'defense' do you have for yours? Mine is at my grandfathers for the winter, but now it has an alarmed disc lock on the front, and the rear is chained to a post with a huge honking chain when out in the wild now; my hope being that people won't mess with it, because they will have to put some major effort into getting it free otherwise.