Hi mike,

> all told problems occured in this second 3dm-file I have attached.

Ok, but you have 150 objects in that file and it's not even zoomed in to any particular area. I need things narrowed down a whole lot to have much of a chance at following what you're talking about.

I just looked at your last image shot, and I selected the surfaces around one of your indicated areas:



And that seemed to join up for me ok.

I need to get a much more focused and narrowed down example from you in order to help you very much. It's very difficult to help you given only pretty general or vague descriptions and when I can't reproduce the problem over here. Please be much more specific and give a file with _only_ the things related to the specific issue you're asking about, that would help a lot.

- Michael