Index: apps/app_meetme.c
===================================================================
--- apps/app_meetme.c	(revision 35574)
+++ apps/app_meetme.c	(working copy)
@@ -819,7 +819,7 @@
 	struct ast_app *app;
 	char *agifile;
 	char *agifiledefault = "conf-background.agi";
-	char meetmesecs[30] = "";
+	char meetmesecs[30] = "", confno[AST_MAX_EXTENSION];
 	char exitcontext[AST_MAX_CONTEXT] = "";
 	char recordingtmp[AST_MAX_EXTENSION] = "";
 	int dtmf;
@@ -832,6 +832,16 @@
 		return ret;
 	}
 
+   	ast_mutex_lock(&conflock);
+
+	/* Make sure we can still find the conference in the list */
+	if (!build_conf(conf->confno, "", "", 0, 0)) {
+		ast_mutex_unlock(&conflock);
+		return -2;
+	}
+
+	ast_copy_string(confno, conf->confno, sizeof(confno));
+
 	if (confflags & CONFFLAG_RECORDCONF && conf->recording !=MEETME_RECORD_ACTIVE) {
 		conf->recordingfilename = pbx_builtin_getvar_helper(chan, "MEETME_RECORDINGFILE");
 		if (!conf->recordingfilename) {
@@ -856,13 +866,13 @@
 		/* Sorry, but this confernce is locked! */	
 		if (!ast_streamfile(chan, "conf-locked", chan->language))
 			ast_waitstream(chan, "");
+		ast_mutex_unlock(&conf_lock);
 		goto outrun;
 	}
 
 	if (confflags & CONFFLAG_MARKEDUSER)
 		conf->markedusers++;
       
-   	ast_mutex_lock(&conflock);
 	if (!conf->firstuser) {
 		/* Fill the first new User struct */
 		user->user_no = 1;
@@ -1035,6 +1045,12 @@
 
 	ast_mutex_lock(&conflock);
 
+	/* Make sure we can still find the conference in the list */
+	if (!build_conf(confno, "", "", 0, 0)) {
+		ast_mutex_unlock(&conflock);
+		return -2;
+	}
+
 	if (!(confflags & CONFFLAG_QUIET) && (confflags & CONFFLAG_INTROUSER) && conf->users > 1) {
 		if (conf->chan && ast_fileexists(user->namerecloc, NULL, NULL)) {
 			if (!ast_streamfile(conf->chan, user->namerecloc, chan->language))
@@ -1548,6 +1564,13 @@
 	reset_volumes(user);
 
 	ast_mutex_lock(&conflock);
+
+	/* Make sure we can still find the conference in the list */
+	if (!build_conf(confno, "", "", 0, 0)) {
+		ast_mutex_unlock(&conflock);
+		return -2;
+	}
+
 	if (!(confflags & CONFFLAG_QUIET) && !(confflags & CONFFLAG_MONITOR) && !(confflags & CONFFLAG_ADMIN))
 		conf_play(chan, conf, LEAVE);
 
@@ -1567,6 +1590,12 @@
  outrun:
 	ast_mutex_lock(&conflock);
 
+	/* Make sure we can still find the conference in the list */
+	if (!build_conf(confno, "", "", 0, 0)) {
+		ast_mutex_unlock(&conflock);
+		return -2;
+	}
+
 	if (confflags & CONFFLAG_MONITORTALKER && dsp)
 		ast_dsp_free(dsp);
 	
@@ -1740,12 +1769,14 @@
 		return -1;
 	}
 	
-	confnum = strsep(&localdata,"|");       
+	confnum = strsep(&localdata, "|");
+	ast_mutex_lock(&conf_lock);
 	conf = find_conf(chan, confnum, 0, 0, NULL, NULL);
 	if (conf)
 		count = conf->users;
 	else
 		count = 0;
+	ast_mutex_unlock(&conf_lock);
 
 	if (!ast_strlen_zero(localdata)){
 		/* have var so load it and exit */
@@ -1927,9 +1958,12 @@
 			}
 		}
 		if (!ast_strlen_zero(confno)) {
+refind_conf:
 			/* Check the validity of the conference */
+			ast_mutex_lock(&conf_lock);
 			cnf = find_conf(chan, confno, 1, dynamic, the_pin, &confflags);
 			if (!cnf) {
+				ast_mutex_unlock(&conf_lock);
 				res = ast_streamfile(chan, "conf-invalid", chan->language);
 				if (!res)
 					ast_waitstream(chan, "");
@@ -1937,6 +1971,12 @@
 				if (allowretry)
 					confno[0] = '\0';
 			} else {
+				char cnfpin[AST_MAX_EXTENSION], cnfpinadmin[AST_MAX_EXTENSION];
+
+				ast_copy_string(cnfpin, cnf->pin, sizeof(cnfpin));
+				ast_copy_string(cnfpinadmin, cnf->pinadmin, sizeof(cnfpinadmin));
+				ast_mutex_unlock(&conf_lock);
+
 				if ((!ast_strlen_zero(cnf->pin) &&
 				     !ast_test_flag(&confflags, CONFFLAG_ADMIN)) ||
 				    (!ast_strlen_zero(cnf->pinadmin) &&
@@ -1954,15 +1994,19 @@
 							res = ast_app_getdata(chan, "conf-getpin", pin + strlen(pin), sizeof(pin) - 1 - strlen(pin), 0);
 						}
 						if (res >= 0) {
-							if (!strcasecmp(pin, cnf->pin) ||
-							    (!ast_strlen_zero(cnf->pinadmin) &&
-							     !strcasecmp(pin, cnf->pinadmin))) {
+							if (!strcasecmp(pin, cnfpin) ||
+							    (!ast_strlen_zero(cnfpinadmin) &&
+							     !strcasecmp(pin, cnfpinadmin))) {
 								/* Pin correct */
 								allowretry = 0;
-								if (!ast_strlen_zero(cnf->pinadmin) && !strcasecmp(pin, cnf->pinadmin)) 
+								if (!ast_strlen_zero(cnfpinadmin) && !strcasecmp(pin, cnfpinadmin)) 
 									ast_set_flag(&confflags, CONFFLAG_ADMIN);
 								/* Run the conference */
 								res = conf_run(chan, cnf, confflags.flags);
+								if (res == -2) {
+									ast_copy_string(the_pin, pin, sizeof(the_pin));
+									goto refind_conf;
+								}
 								break;
 							} else {
 								/* Pin invalid */
@@ -2004,6 +2048,8 @@
 
 					/* Run the conference */
 					res = conf_run(chan, cnf, confflags.flags);
+					if (res == -2)
+						goto refind_conf;
 				}
 			}
 		}