[kisito]

I think it depends on where you are. In a society where parents are well educated, they can be of much help to teachers. But I have taught in places where lots of parents want to give their children the best, but don't know how to go about it. These are usually wealthy parents with a very low academic profile(rich but had dropped outta school early to pursue business and money) . So they come up with some horrible ideas on how to best teach their kids English. It can also seem arrogant to some teachers that some parents want to tell you what to do.
I remember a parent telling me that I don't teach well because when he asks his daughter "What did you learn today?", she cannot say it. It turns out this is my most communicative student in class. The girl's father is clearly a domestic tyrant and so his daughter doesn't even feel free talking to him. So he asked for his money back because he had never heard his daughter say a word in English. It is funny that this guy doesn't even speak a word of English. After so much arguing I deviced a plan to have a chat with the girl all alone with a hidden microphone. I talked to her for 30 mins in English non-stop and she freely expressed herself as she usually did in class. I then secretly handed the mp3 recording to her dad and asked him to listen to the recording privately. He became convinced and surprised that his daughter could speak so much English. I had to politely tell him to go easy on his daughter at home. He felt a bit embarrassed.
I can go on with many similar encounters. It is just stressful dealing with such parents.
On the other hand I have taught in places where parents at least attained a high level of Education and they can be very supportive. It also doesn't take long to explain what we do to them. These parents end up helping the teacher tremendously.