freebsd stable - Jun 2009 - Changes in the routing socket datagram between 7.0 and 7.2?

Did we change something in the routing socket's datagram between 7.0 and
7.2?  I have a binary I compiled on 7.0-RELEASE and it fails to add a route
on 7.2.  If I recompile the source on 7.2, it works.  Roughly put, the code
make a datagram for the route socket like this:

        bzero(&rtmsg, sizeof(rtmsg));

        /* Initial static part of the route message */
        rtmsg.mrtm.rtm_msglen = sizeof(rtmsg);
        rtmsg.mrtm.rtm_type = RTM_ADD;
        rtmsg.mrtm.rtm_flags = RTF_UP | RTF_STATIC | RTF_GATEWAY;
        rtmsg.mrtm.rtm_version = RTM_VERSION;
        rtmsg.mrtm.rtm_addrs = RTA_DST | RTA_GATEWAY | RTA_NETMASK;
        /* Gateway will always be the same */
        rtmsg.gateway.sin_family = AF_INET;
        rtmsg.gateway.sin_len = sizeof(rtmsg.gateway);

        /* Add a route to localhost for my address first */
        rtmsg.dest.sin_addr.s_addr = cons->LtunAddr;
        rtmsg.mask.sin_addr.s_addr = INADDR_BROADCAST;
        rtmsg.mrtm.rtm_seq = htons(fsd->routeSeq++);
        rtmsg.gateway.sin_addr.s_addr = INADDR_LOOPBACK;