My experience is that what you are suggesting - i.e. say thank you and also let the person know your problem is solved - is sort of the standard here, but not just here.
However I have of course been in a situation where the person just never replied, be it here, Skype, email. Sometimes they only get back to you a few days later when they run into another problem and in such case I cant resist to ask how is the other problem. Usually the answer is "Ahhh... yes that is ok now". I guess some people (minorty) do not realize this and once their problem is solved they think "oh yes, great, let´s move on" and sort of take it for granted you help them....
I wouldn´t worry about this too much, there are all sorts of people
Fortunately I think this forum is very good at this, very few trolls and usually extremely nice people.