I have the same problem as mine started to play up at 75000kms and fixed itself.
It has now hit 80000kms and wont budge, even the trip meter has stopped.
So I pulled it apart today and had a look seemed easy enough but I couldn't find anything wrong so I just pushed the odometer numbers gently past 80000 with a small screwdriver.
Dunno if this has worked yet as my radiator is out and I cant drive it.
Will let you know as soon as I do tho.
On a side note my boost guage seems to be playing up.
When Im idling the guage reads 0 pressure not vacuum, but when I start to boost it it climbs up.
Also noticed that when the car is off it falls down to 7 deg vacuum.
Any ideas????