Still slightly confused but now how a working computer.

My local store saved the day - after their mechanic gave up an afternoon to sort this. The Incite 8i that I was trying to pair with a speedtrap turns out to be 'analogue' and not digital as it needs to be.

He upgraded my computer to the digital Trek Incite ACH Digital to solve the problem. This was really kind as the ACH is way more expensive than the 8i that I originally bought.

My observations ...
1) Trek really need to sort out a clear message for the Speedtrap as to what works and what doesn't to avoid any one else this frustration.
2) The 'Bike Factory' in Chester (north west United Kingdom) gives fantastic customer service and I'll never spend money in any other bike store.

M