Why it can not work after I delete breakpoint.(attach the CSocketFile object to a CArchive)

class CChatSocket : public CSocket
{
....
}
void CChatSocket::OnReceive(int nErrorCode)
{
CSocket::OnReceive(nErrorCode);//Here I insert a breakpoint,

m_pDoc->ProcessPendingRead();
}


It works well if I insert a breakpoint int the CHATTER (Client). but If I
delete that breakpoint, OnReceive function can not receive anything.




the source code is in MSDN (CHATTER and CHATSRVR)