QUOTE(Scooby Doo @ May 31 2012, 12:34 PM)

Problems can arise when the parent is the one who is keen for the child to continue, but the child doesn't want to learn (ie doesn't enjoy lessons, doesn't practise etc). Who is the customer in this situation? Surely a student-centred approach in this situation is to tackle the issue and end the lessons if need be? It's all very well saying that we should let them make the decision, but realistically, they aren't always going to get the message that things aren't working.
I don't disagree at all, Scooby Doo. If the student doesn't want to learn and they are, in a way, attending lessons against their will, we have to discuss the issue (with the parent, if applicable). Sometimes things will change, often they won't, and then it's time to say goodbye.
To play they devil's advocate though: "Things aren't working" is relative.
For whom? If both parties are clear that no progress is being made, and the student doesn't really want to be there, the case is straightforward.
What though if it is just our assumption that things aren't working, because of our expectations as professional musicians? The student's expectations might not be that high. They might be perfectly happy to just come to their lesson once a week and find it quite "therapeutic" to just play, even if realistically, they don't make much progress. That's what I meant about communication being a crucial factor. We might not massively enjoy teaching students who don't have goals. In that case, maybe we should focus on just teaching (semi)pros.
There are many ways around the issue if we are clear about what our preferred type of clientele is, and what we are able to put up with. If we e.g. repeatedly get fed up with students who don't have high(ish) aspirations, we have to look into teaching a different clientele (solution A), or make peace with the fact that if we want to/have to teach all levels and abilities, there will always be ones who are maybe not "our favourite type of student" (solution B).
To give you two very similar (only at first glance though) examples from own experience:
Student A: Very busy self-employed person, often has to cancel last minute (has no problem with paying for this), enjoys their lessons though when they can attend and is happy with slow progress. I keep them on. No problem for me since the issue has been discussed, and they are completely clear about the fact I cannot be held responsible for virtually no progress.
Student B: Also very busy business person, cancels constantly last minute (sometimes without notice), always moans they still have to pay (although they always do in the end), gets impatient during the few lessons they actually DO attend. I have an honest chat with them, they feel they are not getting enough out of lessons (and a bit hidden, they actually imply they should be more advanced after over a year of lessons, when in fact, they probably only attended 4 months' worth). We decide to terminate lessons there and then (and I don't insist on any notice periods in that case, because it's in a way me who instigated the whole thing). Fine by me as well.
I don't have any clue what the OP's particular problems with this student are, but I would advise, in any given case, to be aware of the fact that sometimes, it is not the student, but our expectations that make teaching relationships tricky.
BabyGrand's case might be totally obvious, they don't pay on time, are rude, whatever. Then I'd say: Stop it there and then, you don't need to put up with bad behaviour.
If there are other reasons, the case might not be so clear-cut and require a bit more thought.