Can people gain squatters' rights?

What are the rules about rights to land in France?

Q1: WE BOUGHT a property in Poitou-Charentes ten years ago. We had a verbal agreement with our neighbour that small pieces of her land would be exchanged for two pieces we owned which more logically belonged to her property. One of the pieces of land for our use is at the back of our gite and contains its septic tank.
There was no legal document drawn up and now the new owner of the next door property does not want to continue the arrangement. I have been told that in French law there is something about rights accruing through custom and practice - is that true?
Q2: We own two lock up garages at the end of the garden which we do not use. We allow a neighbour to use them, free of charge.
There has been no official paperwork. Could he gain "squatters rights" and demand the right to remain should we wish to cancel the arrangement?

Notaire François Trémosa of the Groupe Monassier in Toulouse said no rights are accrued in such cases - bad news in the first case, but not the second.

In France, the main situation in which rights over land can be obtained merely through use as though you were the owner is called prescription acquisitive and it comes into play after 30 years of uninterrupted use with no complaint from a former owner. This right has to be formalised by a judge.