Here is one thing that really annoyed me about science-related forums: The constant change of the topic by a person, who is obviously just afraid that he'll/she'll look ignorant, incompetent or lazy if he'd/she'd admit that his/her problem was, in fact, solved. Everything turns into an unpleasant "ego battle" that obviously has nothing constructive and with learning quality approaching zero.
As far as I understand, isn't the "Stack Exchange paradigm" supposed to deal with such a disruptive behavior?
Well, I don't want to point fingers, but my first attempt to participate on this (great, I must admit) site led to exactly the same kind of problems. After my answer, the question was totally changed. Also I was downvoted by the guy who asked -- not to complain, just to note that it is obviously just another "ego issue".
I understand that there are a lot of people who somehow make the site running without facing such issues. So I might conclude that the problem is actually in me, and the only thing that suits me is blogging.
Alternatively, maybe have someone faced a similar situation and thinks that it could be useful to have a restriction on the amount of re-editing of questions?