Hello and Good Day. I'v got the answer, from a Dutch Forum, called 'Nucia'.
To inform you about this I will TRY to translate the Dutch answer, that solved the problem, in English:
I changed something in the autorun.inf root of the LaCie disk. (And that guy made for me the blue LaCie icon with the .ico extension, that I dropped in the root of LaCie).
In the root was:
And I changed it to:
Not complicated but to find exactly THIS solution was a long, long way....
I hope that it is quite clear now. The problem is solved over here.
Thanks for help and thinking. Greetings from Holland! PitrPaulus.