Thanks for your help. I also checked this method and it works but this tool is very important for me when I have to create a model for a huge building. There is plenty places where I have to change duct's directions and I need this tool should work properly like for example in this movie (from 4:40)
https://www.youtube.com/watch?v=Pf6FN_xWLtA
I tried to set the same setiings as on a movie and it still doesn't work. I think settings for this tool are also defined somewhere else but I don't know where.
Does anyone have similar problem? I would be grateful for any help.