急！ 阻塞式TCP线程中止问题(50分)

[?]用BCB编程，采用TCP Client与对方的TCP Server通讯，每个端口对应一个线程。如果开的线程2个以下，没有什么问题，如果开50个以上，并且通讯条件不太稳

定的情况下，运行20分钟后常会有线程中断。跟踪发现好像是在open()或Send()的时候返不回来。现在用的是阻塞模式。轻大家帮忙看看问题何在，如何解决？

谢谢！！ 源代码如下：
BOOL TKHTCPComm::Open()
{

DWORD dwError;
char szTmp[100] ;
hostent* he;
int addr;
in_addr in;
int i;

IsOpening = true;
if( !InitFlag )
{
if (WSAStartup(MAKEWORD(2,0),&WSAData) )
{
WSACleanup();
return false;
}
else
InitFlag = true ;
}


to.sin_family = AF_INET;
to.sin_port = htons((unsigned short )RemotePort);
if(FRemoteHost != "" && FRemoteIP == "127.0.0.1" )
{
he = gethostbyname(FRemoteHost.c_str());
memcpy( &addr, he->h_addr_list[0],sizeof(int));
to.sin_addr.s_addr = addr ;
FRemoteIP = inet_ntoa( to.sin_addr ) ;
}
else
to.sin_addr.s_addr = inet_addr(RemoteIP.c_str());
sockfd=socket(AF_INET,SOCK_STREAM,0);

if (sockfd==INVALID_SOCKET)
{
goto exitfail;
}


if (setsockopt(sockfd,SOL_SOCKET,SO_REUSEADDR,(char FAR*)&optval,
sizeof(optval))==SOCKET_ERROR)
{
goto exitfail;
closesocket(sockfd);
return FALSE;
}
ZeroMemory(&server,sizeof(struct sockaddr_in));
server.sin_family=AF_INET;
server.sin_port= htons(RemotePort);
server.sin_addr.s_addr = inet_addr ( FRemoteIP.c_str() );//TCP

if( connect( sockfd , (sockaddr*)&server ,sizeof( server ) ) ==-1 )
{
goto exitfail;
}

if( LocalPort == 0 )
{
int len1,len = sizeof( server );
if( len1 = getsockname( sockfd,(sockaddr*)&server,&len))
{
}
LocalPort = htons( server.sin_port );
}
wasEvent = WSACreateEvent();
if ( WSAEventSelect(sockfd, wasEvent, FD_READ|FD_CLOSE) == SOCKET_ERROR)
{
WSACloseEvent(wasEvent);
closesocket(sockfd);
sockfd = NULL ;
return FALSE;
}
event[0] = wasEvent ;
ConnectFlag = TRUE;
IsOpening = false;
Resume();
Sleep(100);
if( Suspended ) Resume();
return true ;

exitfail:
try
{
i = WSAGetLastError();
closesocket(sockfd);
}
catch(...)
{
i = 1;
}
IsOpening = false ;
ConnectFlag = 0;
return false;
}


发送的源代码如下：
int TKHTCPComm::Send(char *buf,int len)
{
int r;
DWORD dwError;
hostent* he;
int addr;

r = -1;

to.sin_family = AF_INET;
to.sin_port = htons((unsigned short )RemotePort);
if(FRemoteHost != "" && FRemoteIP == "127.0.0.1" )
{
he = gethostbyname(FRemoteHost.c_str());
memcpy( &addr, he->h_addr_list[0],sizeof(int));
to.sin_addr.s_addr = addr ;
FRemoteIP = inet_ntoa( to.sin_addr ) ;
}
else
to.sin_addr.s_addr = inet_addr(RemoteIP.c_str());

if (ConnectFlag)
{
r = sendto (sockfd, buf, len, 0, (struct sockaddr FAR *)&to, sizeof(SOCKADDR));
if (r == SOCKET_ERROR)
{
dwError = WSAGetLastError();
Close();

}
}
return r;
}

[]没有人知道吗 ？
就是进入connect或send()后出不来了，导致线程中止！