Matiz Judder?

[ChevTrev]

I have now owned a three year old 1.0 SE for a week and have found that if I accelerate slowly, it judders mainly in second gear, almost like fuel starvation. My dealer says that the in-car computer may be set for the previous owner who pulled away faster? I'm not a mechanic, but this does not quite sound right... Has anyone else heard of this and has an answer before I take it back?

Also, the in-set dashboard immobiliser light does not come on... the dealer says that it does not in some models? Again, can't be true... can it?

Lastly, does anyone have any recommendations for a simple but effective alarm that works well in the Matiz.
Otherwise, I love this car, it has so much character and does more than twice the MPG of my last car!
Thank you for your time at looking at this, all suggestions welcome!