Ah, this is good to know, I'd been having the same problem and almost given up.
Is there a general guide anywhere to using the editors? I think I've got most the basics sussed as a lot of it is very intuitive (profuse thanks, by the way), although because of the above issue haven't actually tested my modified trees yet, but it would be good to have some guidance. I'd never have figured this out on my own, for example, and I'm sure there are other common issues that will stump a beginner-level modder such as myself.