Confused about some eggs

do someone know, why some eggs get transparent "windos"?
and why some eggs "sweating"?

The windows are usually due to a lack of calcium in that spot. There is nothing you can do about it, as the female is the one that does that. I have rarely had a problem with a window. I do however put liquid band-aid over most of my windows and never had a problem.

As for sweating eggs, extra care should be taken to dry the spot off as often as you can. I normally have poor luck saving an egg that is sweating early in incubation. In my opinion, typically a sweating egg is due to a dead embryo. When the egg starts decomposing, it generates heat and begins to sweat.

Those are my observations, and I hope they help,

Thanks!
but
I´ve got the feeling that these windows are growing :confused:

Windows do grow.

It may be because of several reasons, but my first inclination is to check your humidity and make sure that egg is not overly wet.

it does sound like a humidity problem

I use a Perlite and Vermiculite mix (about 50/50)
and use 30% weight-ratio of water.
It feels verry dry and there is also no condansation in the boxes.