diff -durN hts-tvheadend-2.11.old//src/iptv_input.c hts-tvheadend-2.11//src/iptv_input.c
--- hts-tvheadend-2.11.old//src/iptv_input.c  2010-01-17 07:51:43.000000000 +1000
+++ hts-tvheadend-2.11//src/iptv_input.c  2010-10-18 16:15:43.000000000 +1100
@@ -283,12 +283,36 @@
 static void
 iptv_transport_stop(th_transport_t *t)
 {
+  struct ip_mreqn m;
+  struct ifreq ifr;
+
   pthread_mutex_lock(&iptv_recvmutex);
   LIST_REMOVE(t, tht_active_link);
   pthread_mutex_unlock(&iptv_recvmutex);

   assert(t->tht_iptv_fd >= 0);

+  /* First, resolve interface name */
+  memset(&ifr, 0, sizeof(ifr));
+  av_strlcpy(ifr.ifr_name, t->tht_iptv_iface, IFNAMSIZ);
+  ifr.ifr_name[IFNAMSIZ - 1] = 0;
+  if(ioctl(t->tht_iptv_fd, SIOCGIFINDEX, &ifr)) {
+    tvhlog(LOG_ERR, "IPTV", "\"%s\" cannot find interface %s",
+    t->tht_identifier, t->tht_iptv_iface);
+  }
+
+  /* Leave multicast group */
+  memset(&m, 0, sizeof(m));
+  m.imr_multiaddr.s_addr = t->tht_iptv_group.s_addr;
+  m.imr_address.s_addr = 0;
+  m.imr_ifindex = ifr.ifr_ifindex;
+
+  if(setsockopt(t->tht_iptv_fd, SOL_IP, IP_DROP_MEMBERSHIP, &m,
+   sizeof(struct ip_mreqn)) == -1) {
+    tvhlog(LOG_ERR, "IPTV", "\"%s\" cannot leave %s -- %s",
+    t->tht_identifier, inet_ntoa(m.imr_multiaddr), strerror(errno));
+  }
+
   close(t->tht_iptv_fd); // Automatically removes fd from epoll set

   t->tht_iptv_fd = -1;