thanks for your reply whiteclaws.
1. both event sheets are included by the one directly assigned to the layout. but the first "on start of layout" is in an "earlier include state" than the second one. anyway, the second one does not work. i did simply try to cut&paste the event into the event sheet with the first "on start of layout" condition, and there it works...in spite of being an own event.
this is really strange, since the other events in the third sheet work fine...its only the "on start of layout"- one thats ignored in it.
hope someone here understands what i mean
2. the opposite is wanted, every enemy instance should be handled itself. but this does not seem to work with the "trigger once" condition.