Mk. IV Nav, part5698

About a year ago I upgraded the Mk.III to Mk. IV, as many of you have done, and last week I cobbled up the 2010 software, and all is fine and dandy.

But what has been bothering mee since the upgrade is that the 'time to arrival' feature does not work. it just shows '--:--'
Everything else works OK, the routing continues in tunnels, the clock works, the distance to taret works fine, so I would imagine all the data required to calculate the TTA is present and accounted for.

Also, I've noticed, in the hidden setup menu, the possibility exists to configure different types of speed sensors, but I haven't dared to fiddle with those settings yet.

I've scoured the internet and used the search on this here board, but so far I've come up blank. :crybaby2:

So if someone here has any relevant info on the matter it would be greatly appreciated !

TIA,

Peter