I have read that too much people is having problems applying DVD 100 Navi on Astra H, Zafira B or Vectra C, because the pointer moves too fast in the map.
DVD 100 Navi doesn't read the speed signal from Can Bus, it uses an analogic speed signal from ABS unit. What I think is: This system was born to Opel Antara and Corsa D, and I think that the first units of DVD 100 Navi have the values of mathematical formula to calculate the correct speed, adjusted only for this two models.
We need to instal a recent firmware/software on the system to apply newest mathematical formula to calculate the correct speed from the analogical speed signal. I think that we need a software version from 2008, for example!
I already tried the 2006 version - 61114 but it doesn't work. Somebody has another software version for DVD 100 Navi?