diff --git a/pjmedia/src/pjmedia/conference.c b/pjmedia/src/pjmedia/conference.c
index 8b53798ad..28d1d5b04 100644
--- a/pjmedia/src/pjmedia/conference.c
+++ b/pjmedia/src/pjmedia/conference.c
@@ -1049,6 +1049,7 @@ PJ_DEF(pj_status_t) pjmedia_conf_disconnect_port( pjmedia_conf *conf,
                                                   unsigned sink_slot )
 {
     struct conf_port *src_port, *dst_port;
+    pj_bool_t no_conn = PJ_FALSE;
     unsigned i;
 
     /* Check arguments */
@@ -1098,9 +1099,12 @@ PJ_DEF(pj_status_t) pjmedia_conf_disconnect_port( pjmedia_conf *conf,
             pjmedia_delay_buf_reset(src_port->delay_buf);
     }
 
+    /* Evaluate connect_cnt with mutex, but pause sound dev outside mutex */
+    no_conn = (conf->connect_cnt == 0);
+
     pj_mutex_unlock(conf->mutex);
 
-    if (conf->connect_cnt == 0) {
+    if (no_conn) {
         pause_sound(conf);
     }
 
diff --git a/pjnath/src/pjnath/upnp.c b/pjnath/src/pjnath/upnp.c
index 0747432a5..0a4dad0a9 100644
--- a/pjnath/src/pjnath/upnp.c
+++ b/pjnath/src/pjnath/upnp.c
@@ -325,12 +325,14 @@ static void add_device(const char *dev_id, const char *url)
 {
     unsigned i;
 
+    pj_mutex_lock(upnp_mgr.mutex);
+
     if (upnp_mgr.igd_cnt >= MAX_DEVS) {
+        pj_mutex_unlock(upnp_mgr.mutex);
         PJ_LOG(3, (THIS_FILE, "Warning: Too many UPnP devices discovered"));
         return;
     }
 
-    pj_mutex_lock(upnp_mgr.mutex);
     for (i = 0; i < upnp_mgr.igd_cnt; i++) {
         if (!pj_strcmp2(&upnp_mgr.igd_devs[i].dev_id, dev_id) &&
             !pj_strcmp2(&upnp_mgr.igd_devs[i].url, url))
@@ -358,6 +360,8 @@ static void set_device_online(const char *dev_id)
 {
     unsigned i;
 
+    pj_mutex_lock(upnp_mgr.mutex);
+
     for (i = 0; i < upnp_mgr.igd_cnt; i++) {
         struct igd *igd = &upnp_mgr.igd_devs[i];
         
@@ -367,15 +371,15 @@ static void set_device_online(const char *dev_id)
 
             if (upnp_mgr.primary_igd_idx < 0) {
                 /* If we don't have a primary IGD, use this. */
-                pj_mutex_lock(upnp_mgr.mutex);
                 upnp_mgr.primary_igd_idx = i;
-                pj_mutex_unlock(upnp_mgr.mutex);
 
                 PJ_LOG(4, (THIS_FILE, "Using primary IGD %s",
                                       upnp_mgr.igd_devs[i].dev_id.ptr));
             }
         }
     }
+
+    pj_mutex_unlock(upnp_mgr.mutex);
 }
 
 /* Update IGD status to offline. */
diff --git a/pjsip-apps/src/pjsua/pjsua_app.c b/pjsip-apps/src/pjsua/pjsua_app.c
index b6eeda348..de0e7b77c 100644
--- a/pjsip-apps/src/pjsua/pjsua_app.c
+++ b/pjsip-apps/src/pjsua/pjsua_app.c
@@ -1111,8 +1111,10 @@ void on_ip_change_progress(pjsua_ip_change_op op,
         case PJSUA_IP_CHANGE_OP_COMPLETED:
             pj_ansi_snprintf(info_str, sizeof(info_str),
                              "done");
+            break;
         default:
-            info_str[0] = '\0';
+            pj_ansi_snprintf(info_str, sizeof(info_str),
+                             "unknown-op");
             break;
         }
         PJ_LOG(3,(THIS_FILE, "IP change progress report : %s", info_str));
diff --git a/pjsip/src/pjsip-simple/publishc.c b/pjsip/src/pjsip-simple/publishc.c
index a18a32f9a..58222eea1 100644
--- a/pjsip/src/pjsip-simple/publishc.c
+++ b/pjsip/src/pjsip-simple/publishc.c
@@ -777,7 +777,6 @@ PJ_DEF(pj_status_t) pjsip_publishc_send(pjsip_publishc *pubc,
             return PJ_EBUSY;
         }
     }
-    pj_mutex_unlock(pubc->mutex);
 
     /* If via_addr is set, use this address for the Via header. */
     if (pubc->via_addr.host.slen > 0) {
@@ -798,6 +797,9 @@ PJ_DEF(pj_status_t) pjsip_publishc_send(pjsip_publishc *pubc,
      * may be called even before send_request() returns!
      */
     ++pubc->pending_tsx;
+
+    pj_mutex_unlock(pubc->mutex);
+
     status = pjsip_endpt_send_request(pubc->endpt, tdata, -1, pubc, 
                                       &tsx_callback);
     if (status!=PJ_SUCCESS) {
diff --git a/pjsip/src/pjsip/sip_transaction.c b/pjsip/src/pjsip/sip_transaction.c
index e89c6d6fa..2f9a80f69 100644
--- a/pjsip/src/pjsip/sip_transaction.c
+++ b/pjsip/src/pjsip/sip_transaction.c
@@ -880,6 +880,7 @@ pjsip_tsx_detect_merged_requests(pjsip_rx_data *rdata)
 {
     pj_str_t key, key2;
     pj_uint32_t hval = 0;
+    pjsip_transaction *tsx = NULL;
     pj_status_t status;
 
     PJ_ASSERT_RETURN(rdata->msg_info.msg->type == PJSIP_REQUEST_MSG, NULL);
@@ -895,12 +896,15 @@ pjsip_tsx_detect_merged_requests(pjsip_rx_data *rdata)
     if (status != PJ_SUCCESS)
         return NULL;
 
+    pj_mutex_lock( mod_tsx_layer.mutex );
+
     /* This request must not match any transaction in our primary hash
      * table.
      */
     if (pj_hash_get_lower(mod_tsx_layer.htable, key.ptr, (unsigned)key.slen,
                           &hval) != NULL)
     {
+        pj_mutex_unlock( mod_tsx_layer.mutex);
         return NULL;
     }
 
@@ -910,14 +914,18 @@ pjsip_tsx_detect_merged_requests(pjsip_rx_data *rdata)
     status = create_tsx_key_2543(rdata->tp_info.pool, &key2, PJSIP_ROLE_UAS,
                                  &rdata->msg_info.cseq->method, rdata,
                                  PJ_FALSE);
-    if (status != PJ_SUCCESS)
+    if (status != PJ_SUCCESS) {
+        pj_mutex_unlock( mod_tsx_layer.mutex);
         return NULL;
+    }
 
     hval = 0;
-    return (pjsip_transaction *) pj_hash_get_lower(mod_tsx_layer.htable2,
-                                                   key2.ptr,
-                                                   (unsigned)key2.slen,
-                                                   &hval);
+    tsx = pj_hash_get_lower(mod_tsx_layer.htable2, key2.ptr,
+                            (unsigned)key2.slen, &hval);
+
+    pj_mutex_unlock( mod_tsx_layer.mutex);
+
+    return tsx;
 }
 
 /* This module callback is called when endpoint has received an