G'day Skydog
Mate quite a few rocket have this problem sooner or later.
I have the 2010 roadster, first time this happened my dealer got in touch with Triumph who provided a loom accessory patch cable.
My dealer told me it may be to late to rectify the problem totally. Now I have the same shut down issue's again.
What actually happens in the ignition switch gets fried every time we start our bikes, all the juice goes through the switch, melting and burning the ignition switch out in the process.
I would be getting onto your dealer where you bought your rocket, check if it was in the recall list, hope for your financial sake it is and it will be fixed for free. all as I'm waiting on is for Triumph to supply the three barrels so I can change not only my ignition switch, but seat and fuel tank locks as well.
Also go through this forum and you'll find links to DYI beaver light relay kits, reasonably price around $80 USD, guarantees you never have the problem again.