I havn't had any problems like this in the past, but socket keeps returning INVALID_SOCKET. WSAGetLastError returns 6, which according to FormatMessage is "The handle is invalid.". If I try creating a IPv4 socket, I get no errors at all.
http://www.microsoft.com/resources/documentation/WindowsServ/2003/standard/proddocs/en-us/Default.asp?url=/resources/documentation/WindowsServ/2003/standard/proddocs/en-us/sag_ip_v6_pro_inst.asp