diff --git a/coreapi/linphonecore_jni.cc b/coreapi/linphonecore_jni.cc
index a56e1d14b..76cbbad5c 100644
--- a/coreapi/linphonecore_jni.cc
+++ b/coreapi/linphonecore_jni.cc
@@ -170,7 +170,7 @@ jobject getProxy(JNIEnv *env, LinphoneProxyConfig *proxy, jobject core){
 	jobject jobj=0;
 
 	if (proxy!=NULL){
-		jclass proxyClass = (jclass)env->NewGlobalRef(env->FindClass("org/linphone/core/LinphoneProxyConfigImpl"));
+		jclass proxyClass = (jclass)env->FindClass("org/linphone/core/LinphoneProxyConfigImpl");
 		jmethodID proxyCtrId = env->GetMethodID(proxyClass,"<init>", "(Lorg/linphone/core/LinphoneCoreImpl;J)V");
 
 		void *up=linphone_proxy_config_get_user_data(proxy);
@@ -188,7 +188,7 @@ jobject getProxy(JNIEnv *env, LinphoneProxyConfig *proxy, jobject core){
 				linphone_proxy_config_set_user_data(proxy,(void*)env->NewWeakGlobalRef(jobj));
 			}
 		}
-		env->DeleteGlobalRef(proxyClass);
+		env->DeleteLocalRef(proxyClass);
 	}
 	return jobj;
 }
@@ -197,7 +197,7 @@ jobject getCall(JNIEnv *env, LinphoneCall *call){
 	jobject jobj=0;
 
 	if (call!=NULL){
-		jclass callClass = (jclass)env->NewGlobalRef(env->FindClass("org/linphone/core/LinphoneCallImpl"));
+		jclass callClass = (jclass)env->FindClass("org/linphone/core/LinphoneCallImpl");
 		jmethodID callCtrId = env->GetMethodID(callClass,"<init>", "(J)V");
 
 		void *up=linphone_call_get_user_pointer(call);
@@ -210,7 +210,7 @@ jobject getCall(JNIEnv *env, LinphoneCall *call){
 		}else{
 			jobj=(jobject)up;
 		}
-		env->DeleteGlobalRef(callClass);
+		env->DeleteLocalRef(callClass);
 	}
 	return jobj;
 }
@@ -219,7 +219,7 @@ jobject getChatMessage(JNIEnv *env, LinphoneChatMessage *msg){
 	jobject jobj = 0;
 
 	if (msg != NULL){
-		jclass chatMessageClass = (jclass)env->NewGlobalRef(env->FindClass("org/linphone/core/LinphoneChatMessageImpl"));
+		jclass chatMessageClass = (jclass)env->FindClass("org/linphone/core/LinphoneChatMessageImpl");
 		jmethodID chatMessageCtrId = env->GetMethodID(chatMessageClass,"<init>", "(J)V");
 
 		void *up = linphone_chat_message_get_user_data(msg);
@@ -231,7 +231,7 @@ jobject getChatMessage(JNIEnv *env, LinphoneChatMessage *msg){
 		} else {
 			jobj = (jobject)up;
 		}
-		env->DeleteGlobalRef(chatMessageClass);
+		env->DeleteLocalRef(chatMessageClass);
 	}
 	return jobj;
 }
@@ -240,14 +240,14 @@ jobject getEvent(JNIEnv *env, LinphoneEvent *lev){
 	if (lev==NULL) return NULL;
 	jobject jev=(jobject)linphone_event_get_user_data(lev);
 	if (jev==NULL){
-		jclass linphoneEventClass = (jclass)env->NewGlobalRef(env->FindClass("org/linphone/core/LinphoneEventImpl"));
+		jclass linphoneEventClass = (jclass)env->FindClass("org/linphone/core/LinphoneEventImpl");
 		jmethodID linphoneEventCtrId = env->GetMethodID(linphoneEventClass,"<init>", "(J)V");
 
 		jev=env->NewObject(linphoneEventClass,linphoneEventCtrId,(jlong)linphone_event_ref(lev));
 		jev=env->NewGlobalRef(jev);
 		linphone_event_set_user_data(lev,jev);
 
-		env->DeleteGlobalRef(linphoneEventClass);
+		env->DeleteLocalRef(linphoneEventClass);
 	}
 	return jev;
 }
@@ -577,7 +577,11 @@ public:
 		}
 		LinphoneCoreVTable *table = linphone_core_get_current_vtable(lc);
 		LinphoneCoreData* lcData = (LinphoneCoreData*)linphone_core_v_table_get_user_data(table);
-		env->CallVoidMethod(lcData->listener,lcData->displayStatusId,lcData->core,message ? env->NewStringUTF(message) : NULL);
+		jstring msg = message ? env->NewStringUTF(message) : NULL;
+		env->CallVoidMethod(lcData->listener,lcData->displayStatusId,lcData->core,msg);
+		if (msg) {
+			env->DeleteLocalRef(msg);
+		}
 	}
 	static void authInfoRequested(LinphoneCore *lc, const char *realm, const char *username, const char *domain) {
 		JNIEnv *env = 0;
@@ -588,12 +592,24 @@ public:
 		}
 		LinphoneCoreVTable *table = linphone_core_get_current_vtable(lc);
 		LinphoneCoreData* lcData = (LinphoneCoreData*)linphone_core_v_table_get_user_data(table);
+		jstring r = realm ? env->NewStringUTF(realm) : NULL;
+		jstring u = username ? env->NewStringUTF(username) : NULL;
+		jstring d = domain ? env->NewStringUTF(domain) : NULL;
 		env->CallVoidMethod(lcData->listener,
 							lcData->authInfoRequestedId,
 							lcData->core,
-							realm ? env->NewStringUTF(realm):NULL,
-							username ? env->NewStringUTF(username) : NULL,
-							domain ? env->NewStringUTF(domain) : NULL);
+							r,
+							u,
+							d);
+		if (r) {
+			env->DeleteLocalRef(r);
+		}
+		if (u) {
+			env->DeleteLocalRef(u);
+		}
+		if (d) {
+			env->DeleteLocalRef(d);
+		}
 	}
 	static void globalStateChange(LinphoneCore *lc, LinphoneGlobalState gstate,const char* message) {
 		JNIEnv *env = 0;
@@ -604,11 +620,15 @@ public:
 		}
 		LinphoneCoreVTable *table = linphone_core_get_current_vtable(lc);
 		LinphoneCoreData* lcData = (LinphoneCoreData*)linphone_core_v_table_get_user_data(table);
+		jstring msg = message ? env->NewStringUTF(message) : NULL;
 		env->CallVoidMethod(lcData->listener
 							,lcData->globalStateId
 							,lcData->core
 							,env->CallStaticObjectMethod(lcData->globalStateClass,lcData->globalStateFromIntId,(jint)gstate),
-							message ? env->NewStringUTF(message) : NULL);
+							msg);
+		if (msg) {
+			env->DeleteLocalRef(msg);
+		}
 	}
 	static void registrationStateChange(LinphoneCore *lc, LinphoneProxyConfig* proxy,LinphoneRegistrationState state,const char* message) {
 		JNIEnv *env = 0;
@@ -620,12 +640,16 @@ public:
 		}
 		LinphoneCoreVTable *table = linphone_core_get_current_vtable(lc);
 		LinphoneCoreData* lcData = (LinphoneCoreData*)linphone_core_v_table_get_user_data(table);
+		jstring msg = message ? env->NewStringUTF(message) : NULL;
 		env->CallVoidMethod(lcData->listener
 							,lcData->registrationStateId
 							,lcData->core
 							,(jproxy=getProxy(env,proxy,lcData->core))
 							,env->CallStaticObjectMethod(lcData->registrationStateClass,lcData->registrationStateFromIntId,(jint)state),
-							message ? env->NewStringUTF(message) : NULL);
+							msg);
+		if (msg) {
+			env->DeleteLocalRef(msg);
+		}
 	}
 
 	static void callStateChange(LinphoneCore *lc, LinphoneCall* call,LinphoneCallState state,const char* message) {
@@ -638,16 +662,20 @@ public:
 		}
 		LinphoneCoreVTable *table = linphone_core_get_current_vtable(lc);
 		LinphoneCoreData* lcData = (LinphoneCoreData*)linphone_core_v_table_get_user_data(table);
+		jstring msg = message ? env->NewStringUTF(message) : NULL;
 		env->CallVoidMethod(lcData->listener
 							,lcData->callStateId
 							,lcData->core
 							,(jcall=getCall(env,call))
 							,env->CallStaticObjectMethod(lcData->callStateClass,lcData->callStateFromIntId,(jint)state),
-							message ? env->NewStringUTF(message) : NULL);
-		if (state==LinphoneCallReleased){
+							msg);
+		if (state==LinphoneCallReleased) {
 			linphone_call_set_user_pointer(call,NULL);
 			env->DeleteGlobalRef(jcall);
 		}
+		if (msg) {
+			env->DeleteLocalRef(msg);
+		}
 	}
 	static void callEncryptionChange(LinphoneCore *lc, LinphoneCall* call, bool_t encrypted,const char* authentication_token) {
 		JNIEnv *env = 0;