Thanx Marilynne.
No, no section Error Messages in the manual.
Before some years I had also a Nikon Coolpix, same problem. I read at forums that a lot of people have this problem. Maybe it is sand? but then it is better not to buy a camera like this. I didn't go to the beach, so what if you go to the beach??
But I will contact the dealer, hope they can do something for me ;-)