Point clouds import problem

Hi, after my last posting I just safe them all 1 by 1, from e57 to RWP no problem it kept me from the street some time.
Now when I import several scans the refences are not correct and some of the same scans are there in different views. Looks like they are over each other.
Anybody now what happens?

Other question is; when I import several scans, is it possible to add more sans later and how?
Thanks in advance for your reactions