--- apps/app_confbridge.c.orig	2012-05-03 15:57:57.400247203 -0600
+++ apps/app_confbridge.c	2012-05-03 19:28:16.688791477 -0600
@@ -610,9 +610,10 @@
 	} else if (conference_bridge->users == 2) {
 		if (conference_bridge_user) {
 			/* Eep, there is one other person */
-			if (ast_stream_and_wait(conference_bridge_user->chan,
+			int res = ast_stream_and_wait(conference_bridge_user->chan,
 				only_one,
-				"")) {
+				"");
+			if (res) {
 				return -1;
 			}
 		} else {
@@ -742,21 +743,24 @@
  */
 static int turn_off_moh(struct conference_bridge *conference_bridge, struct conference_bridge_user *conference_bridge_user)
 {
+    int success = 0;
 	if (conference_bridge_user->playing_moh) {
         if (!conference_bridge_user->forced_moh) {
+            ast_mutex_lock(&conference_bridge_user->suspend_lock);
             if (!ast_bridge_suspend(conference_bridge->bridge, conference_bridge_user->chan)) {
 		        conference_bridge_user->playing_moh = 0;
 		        ast_moh_stop(conference_bridge_user->chan);
 		        ast_bridge_unsuspend(conference_bridge->bridge, conference_bridge_user->chan);
 		        conference_bridge_user->features.mute = conference_bridge_user->forced_mute;
 	        } else {
-	            return -1;
+	            success = -1;
 	        }
+	        ast_mutex_unlock(&conference_bridge_user->suspend_lock);
         } else {
             conference_bridge_user->playing_moh = 0;
         }
 	}
-	return 0;
+	return success;
 }
 
 /*!
@@ -1190,12 +1194,14 @@
 		            }
 	            }
 	            if (!other_participant->playing_moh && !other_participant->forced_moh) {
+	                ast_mutex_lock(&other_participant->suspend_lock);
 			        if (!ast_bridge_suspend(conference_bridge->bridge, other_participant->chan)) {
 			            ast_moh_start(other_participant->chan, other_participant->u_profile.moh_class, NULL);
 			            other_participant->playing_moh = 1;
 			            other_participant->features.mute = 1;
 			            ast_bridge_unsuspend(conference_bridge->bridge, other_participant->chan);
 		            }
+		            ast_mutex_unlock(&other_participant->suspend_lock);
 	            }
 			}
 		}
@@ -1435,6 +1441,7 @@
 		.tech_args.silence_threshold = DEFAULT_SILENCE_THRESHOLD,
 		.tech_args.drop_silence = 0,
 	};
+	ast_mutex_init(&conference_bridge_user.suspend_lock);
 	AST_DECLARE_APP_ARGS(args,
 		AST_APP_ARG(conf_name);
 		AST_APP_ARG(b_profile_name);
@@ -1640,9 +1647,11 @@
 
 	/* If the user was kicked from the conference play back the audio prompt for it */
 	if (!quiet && conference_bridge_user.kicked) {
+	    ast_mutex_lock(&conference_bridge_user.suspend_lock);
 		res = ast_stream_and_wait(chan,
 			conf_get_sound(CONF_SOUND_KICKED, conference_bridge_user.b_profile.sounds),
 			"");
+		ast_mutex_unlock(&conference_bridge_user.suspend_lock);
 	}
 
 	/* Restore volume adjustments to previous values in case they were changed */
@@ -1660,6 +1669,7 @@
 confbridge_cleanup:
 	ast_bridge_features_cleanup(&conference_bridge_user.features);
 	conf_bridge_profile_destroy(&conference_bridge_user.b_profile);
+	ast_mutex_destroy(&conference_bridge_user.suspend_lock);
 	return res;
 }
 
@@ -1673,10 +1683,11 @@
 		conference_bridge_user->forced_mute = conference_bridge_user->features.mute;
 		ast_test_suite_event_notify("CONF_MUTE", "Message: participant %s %s\r\nConference: %s\r\nChannel: %s", ast_channel_name(chan), conference_bridge_user->features.mute ? "muted" : "unmuted", conference_bridge_user->b_profile.name, ast_channel_name(chan));
 	}
-	return ast_stream_and_wait(chan, (conference_bridge_user->features.mute ?
+	int res = ast_stream_and_wait(chan, (conference_bridge_user->features.mute ?
 		conf_get_sound(CONF_SOUND_MUTED, conference_bridge_user->b_profile.sounds) :
 		conf_get_sound(CONF_SOUND_UNMUTED, conference_bridge_user->b_profile.sounds)),
 		"");
+	return res;
 }
 
 static int action_toggle_mute_participants(struct conference_bridge *conference_bridge, struct conference_bridge_user *conference_bridge_user)
@@ -1741,7 +1752,8 @@
 	char *file = NULL;
 
 	while ((file = strsep(&file_copy, "&"))) {
-		if (ast_streamfile(bridge_channel->chan, file, ast_channel_language(bridge_channel->chan))) {
+	    int res = ast_streamfile(bridge_channel->chan, file, ast_channel_language(bridge_channel->chan));
+		if (res) {
 			ast_log(LOG_WARNING, "Failed to playback file %s to channel\n", file);
 			return -1;
 		}
@@ -1950,7 +1962,6 @@
 				conf_get_sound(CONF_SOUND_LOCKED_NOW, conference_bridge_user->b_profile.sounds) :
 				conf_get_sound(CONF_SOUND_UNLOCKED_NOW, conference_bridge_user->b_profile.sounds)),
 				"");
-
 			break;
 		case MENU_ACTION_ADMIN_KICK_LAST:
 			res |= action_kick_last(conference_bridge, bridge_channel, conference_bridge_user);
@@ -2191,15 +2202,19 @@
 	if (participant) {
 	    if (!participant->playing_moh) { /* If the participant is playing MoH naturally, let it do its thing */
             if (moh && !participant->forced_moh) {
+                ast_mutex_lock(&participant->suspend_lock);
 	            if (!ast_bridge_suspend(bridge->bridge, participant->chan)) {
                     ast_moh_start(participant->chan, participant->u_profile.moh_class, NULL);
                     ast_bridge_unsuspend(bridge->bridge, participant->chan);
                 }
+                ast_mutex_unlock(&participant->suspend_lock);
 	        } else if (!moh && participant->forced_moh) {
+	            ast_mutex_lock(&participant->suspend_lock);
 	            if (!ast_bridge_suspend(bridge->bridge, participant->chan)) {
 	                ast_moh_stop(participant->chan);
      	            ast_bridge_unsuspend(bridge->bridge, participant->chan);
-                 }
+                }
+                ast_mutex_unlock(&participant->suspend_lock);
 	        }
         }
         /* Set flags regardless of natural state */
@@ -2322,8 +2337,9 @@
 static void *action_confbridgeplayfile_thread(void *obj)
 {
 	struct action_confbridgeplayfile_specifier *specifier = (struct action_confbridgeplayfile_specifier *)obj;
-
+    
 	if (specifier->participant) {
+	    ast_mutex_lock(&specifier->participant->suspend_lock);
 	    if (!ast_bridge_suspend(specifier->bridge->bridge, specifier->participant->chan)) {
 	        if(specifier->participant->playing_moh || specifier->participant->forced_moh){
 				ast_moh_stop(specifier->participant->chan);
@@ -2338,6 +2354,7 @@
 			}
 			ast_bridge_unsuspend(specifier->bridge->bridge, specifier->participant->chan);
 		}
+		ast_mutex_unlock(&specifier->participant->suspend_lock);
 	} else {
 	    play_sound_helper(specifier->bridge, (const char *)&specifier->file, 0);
     }
--- apps/confbridge/include/confbridge.h.orig	2012-05-03 18:42:51.772673952 -0600
+++ apps/confbridge/include/confbridge.h	2012-05-03 19:16:02.116759795 -0600
@@ -232,6 +232,7 @@
 	unsigned int forced_moh:1;                   /*!< The user has been explicitly placed on hold and should not be subject to automatic toggles */
 	unsigned int forced_mute:1;                   /*!< The user has been explicitly placed on hold and should not be subject to automatic toggles */
 	AST_LIST_ENTRY(conference_bridge_user) list; /*!< Linked list information */
+	ast_mutex_t suspend_lock;                    /*!< Lock used to prevent channel-suspensions from encountering race conditions */
 };
 
 /*! \brief load confbridge.conf file */