Multicast is not working on Windows Vista

Question

While I try to Multicast something to range of IP in win XP , it works fine but while I run the same application on Win VIsta I am unable to multicast. Do I need to configure or add a publisher info for Win Vitsa?

Edit:

struct sockaddr_in staddr;
    memset(&staddr, 0, sizeof(struct sockaddr_in));
    staddr.sin_family = AF_INET;
    staddr.sin_port = htons(SSDP_PORT); // Use the first free port
    staddr.sin_addr.s_addr=inet_addr(SSDP_MULTICAST_ADDRESS);

    int socklen = sizeof(struct sockaddr_in);

Edit 2

Socket Creation
int ibindstatus =0 ;
    try
    {
    //Initailize the WinSock
    WSADATA wsaData;
    WSAStartup(MAKEWORD(2,2), &wsaData);

   struct in_addr iaddr;
   struct sockaddr_in staddr;
   // set content of struct saddr and imreq to zero
   memset(&staddr, 0, sizeof(struct sockaddr_in));
   memset(&iaddr, 0, sizeof(struct in_addr));

   // open a UDP socket

   m_iSocket = socket(AF_INET, SOCK_DGRAM, 0);
   if ( m_iSocket < 0 )     
    {       
      return SOCKET_NOT_AVAILABLE;
    } 

   staddr.sin_family = AF_INET;
   staddr.sin_port = htons(SSDP_PORT); // Use the first free port
   staddr.sin_addr.s_addr = htonl(INADDR_ANY); // bind socket to any interface 

   ibindstatus = bind(m_iSocket, (struct sockaddr *)&staddr, sizeof(struct sockaddr_in));
   if ( ibindstatus < 0 )
   {
      return SOCKET_BIND_ERROR;
   }


    //send the buffer
    int iSendStatus = sendto(m_iSocket, cSendData, lSendDataLen, 0,
                     (struct sockaddr *)&staddr, socklen);  
    if(iSendStatus< 0)
    {
       return SEND_ERROR;      
    }

Answer 1

Well after lotz of experiments I was not able to figure out why Multi casting was not working, and found out suddenly this is because Network Discovery was off on my Vista.

So If here what I did , Go to Control Panel->SetUp File Sharing(Under Network and Internet) ->Sharing and Discovery and then switch on or off the network discovery

Well thatz what work for my application and the source code is what I have posted in my question. Hope fully this will save some of your time and frustation.