Got the bike back from the dealer last night.
Their story is that Triumph has never heard of this problem before, which is obviously a complete load of BS. I don't know whether I should believe these guys and that Triumph is lying through their teeth, or think that the dealership is full of it.
when I first told my dealer about the speedo problem they on the phone with triumph in the UK straight away, and apparently got sugestions about what to try.
as a side note: a co-worker when on a factory demo t-bird (from the factory demo truck) and mentioned the speedometer was stuck, Triumph must be aware of this problem by now. The demo bird was also turning the right header bright blue at the top bend, not so good.