Windows UDP sendto returns WSAEINTR

Question

I have a UDP socket that is opened for output only. Here are the pertinent calls (I left out the error handling to make it easier to read):

rc = WSAStartup(MAKEWORD(2, 2), &wsd);

so = WSASocket(AF_INET, SOCK_DGRAM, IPPROTO_UDP, 0, 0, 0);

sendto(so, buf, bufLen, 0, (SOCKADDR *) &dest, sizeof(dest));

This socket is only written to. Occasionally, the sendto call returns a WSAEINTR error. Once I get this error, all subsequent sendto calls return this error.

Can anyone provide some reasons why I would get this error? I never wait on this socket and I never close it.

Thanks...