what is the cause of walking/talking while sleeping ?

I don't know the cause but my son talks in his sleep. Chats away and sings, bless. I don't think I do, have never been told I do so I guess not. My son is the only one that I know who does, so I don't even know how common a problem it is. Ellie :D

Yes my uncle has this disorder. He talks while he sleeps and he also tries walking. This is usully genetic or it can also be a disease related to the brain. I dont know what the disease is called but yes i know that it is a disease.

I suspect the reason is that the mind is too active. The mind would likely be thinking about related things (those that he utters in his sleep) during his waking hours in the day. So at night, though the body is in deep rest, the mind continues to ponder the questions. Even if the topics don't seem related at first glance, I suspect that they are since everything is inter-related and one leads to the other.

I don't know for sure but I can tell you what i have heard about this matter..I have heard somewhere that whenever you do something that makes you really use your brain before you go to bed...like when kids play video games...their mind is still active when they are trying to go to sleep so it just amkes them do that stuff

notice why this kind of things usually happens to children? i believe this is from lack of sleep. they will outgrow this. well majority of them.