Threads and sockets

Question

Hi all... I have a question when using sockets in threads. I have a class "A" that creates another "B" in a thread. B then creates a server side socket. B is global in A. If the thread in A exits I get an error saying that I/O request failed because a thread exited or an application request it. If I include a sleep in the thread so it does not exit, it works fine. Can anyone explain me this behaviour of threads and sockets? Thanks. Regards, Sandra