Been to look at it tonight, and it's looking like the clutch and/or release bearing.
It'll have to wait until I'm back from holiday for further analysis though
The exact same thing happened to me yesterday, well it started the nite before
while trying to put the car in a lot.
When I want R, it wouldn't move, just stayed in N.
So i turned of the engine, waited abit then turn it to MAR and heard the pump and
then it shifted fine.
The next day, it happened again, this time at a traffic junction in a main street, on a hot Saturday afternoon and I was holding up traffic for 2-3 light change.
Was in 1st ( I usually don't drive in City mode ) and it jumped to N, while I was waiting
for the lights to go green and my foot on the brakes.
Went thru the "off engine ritual" again but this time it took a good 3mins after 2-3 tries before it would shift again.
Then I drove in city mode, thinking maybe it would rid itself of the problem . . . .
But alas, it happened again, while in 3rd, I slowed to a almost complete stop before it woun't down shift and then when I came to a complete stop, it went to N and stayed there.
Took alot of coaxing again before it would shift again.
It's in a Alfa specialist workshop now.
Any ideas of the cause . . . . . once or twice recently, I had the " selespeed failure" light come on for a second or two, usually when the engine is cold.