diff --git a/coreapi/bellesip_sal/sal_impl.h b/coreapi/bellesip_sal/sal_impl.h
index 424fc6961..f6f395fb5 100644
--- a/coreapi/bellesip_sal/sal_impl.h
+++ b/coreapi/bellesip_sal/sal_impl.h
@@ -81,7 +81,7 @@ void set_or_update_dialog(SalOp* op, belle_sip_dialog_t* dialog);
 
 void sal_op_set_remote_ua(SalOp*op,belle_sip_message_t* message);
 int sal_op_send_request(SalOp* op, belle_sip_request_t* request);
-int sal_op_send_request_with_contact(SalOp* op, belle_sip_request_t* request) ;
+
 void sal_op_resend_request(SalOp* op, belle_sip_request_t* request);
 void sal_process_authentication(SalOp *op, belle_sip_response_t *response);
 belle_sip_header_contact_t* sal_op_create_contact(SalOp *op,belle_sip_header_from_t* from_header) ;
diff --git a/coreapi/bellesip_sal/sal_op_call.c b/coreapi/bellesip_sal/sal_op_call.c
index c75eb0e18..611ddf62f 100644
--- a/coreapi/bellesip_sal/sal_op_call.c
+++ b/coreapi/bellesip_sal/sal_op_call.c
@@ -430,9 +430,9 @@ int sal_call(SalOp *op, const char *from, const char *to){
 				belle_sip_message_add_header(BELLE_SIP_MESSAGE(invite),BELLE_SIP_HEADER(op->referred_by));
 	}
 
-	sal_op_send_request_with_contact(op,invite);
+	return sal_op_send_request(op,invite);
+
 
-	return 0;
 }
 void sal_op_call_fill_cbs(SalOp*op) {
 	op->callbacks.process_io_error=call_process_io_error;
@@ -549,7 +549,7 @@ int sal_call_update(SalOp *op, const char *subject){
 	belle_sip_request_t *reinvite=belle_sip_dialog_create_request(op->dialog,"INVITE");
 	belle_sip_message_add_header(BELLE_SIP_MESSAGE(reinvite),belle_sip_header_create( "Subject", subject));
 	sal_op_fill_invite(op, reinvite);
-	return sal_op_send_request_with_contact(op,reinvite);
+	return sal_op_send_request(op,reinvite);
 }
 SalMediaDescription * sal_call_get_remote_media_description(SalOp *h){
 	return h->base.remote_media;;
diff --git a/coreapi/bellesip_sal/sal_op_impl.c b/coreapi/bellesip_sal/sal_op_impl.c
index 7f052e358..8f3254460 100644
--- a/coreapi/bellesip_sal/sal_op_impl.c
+++ b/coreapi/bellesip_sal/sal_op_impl.c
@@ -151,6 +151,7 @@ static int _sal_op_send_request_with_contact(SalOp* op, belle_sip_request_t* req
 	}
 	if (add_contact) {
 		contact = sal_op_create_contact(op,belle_sip_message_get_header_by_type(BELLE_SIP_MESSAGE(request),belle_sip_header_from_t));
+		belle_sip_message_remove_header(BELLE_SIP_MESSAGE(request),BELLE_SIP_CONTACT);
 		belle_sip_message_add_header(BELLE_SIP_MESSAGE(request),BELLE_SIP_HEADER(contact));
 	}
 	if (!belle_sip_message_get_header(BELLE_SIP_MESSAGE(request),BELLE_SIP_AUTHORIZATION)
@@ -163,12 +164,22 @@ static int _sal_op_send_request_with_contact(SalOp* op, belle_sip_request_t* req
 }
 
 int sal_op_send_request(SalOp* op, belle_sip_request_t* request)  {
-	return _sal_op_send_request_with_contact(op, request,FALSE);
-}
-int sal_op_send_request_with_contact(SalOp* op, belle_sip_request_t* request) {
-	return _sal_op_send_request_with_contact(op, request,TRUE);
+	bool_t need_ack=FALSE;
+	/*
+  	  Header field          where   proxy ACK BYE CAN INV OPT REG
+      ___________________________________________________________
+      Contact                 R            o   -   -   m   o   o
+	 */
+	if (strcmp(belle_sip_request_get_method(request),"INVITE")==0
+			||strcmp(belle_sip_request_get_method(request),"REGISTER")==0
+			||strcmp(belle_sip_request_get_method(request),"SUBSCRIBE")==0
+			||strcmp(belle_sip_request_get_method(request),"OPTION")==0)
+		need_ack=TRUE;
+
+	return _sal_op_send_request_with_contact(op, request,need_ack);
 }
 
+
 void sal_compute_sal_errors_from_code(int code ,SalError* sal_err,SalReason* sal_reason) {
 		switch(code) {
 		case 400:
diff --git a/coreapi/bellesip_sal/sal_op_presence.c b/coreapi/bellesip_sal/sal_op_presence.c
index 590a92a18..9da9e1080 100644
--- a/coreapi/bellesip_sal/sal_op_presence.c
+++ b/coreapi/bellesip_sal/sal_op_presence.c
@@ -591,7 +591,7 @@ int sal_subscribe_presence(SalOp *op, const char *from, const char *to){
 	belle_sip_message_add_header(BELLE_SIP_MESSAGE(req),belle_sip_header_create("Event","Presence"));
 	belle_sip_message_add_header(BELLE_SIP_MESSAGE(req),BELLE_SIP_HEADER(belle_sip_header_expires_create(600)));
 
-	return sal_op_send_request_with_contact(op,req);
+	return sal_op_send_request(op,req);
 }
 int sal_unsubscribe(SalOp *op){
 	belle_sip_request_t* req=op->dialog?belle_sip_dialog_create_request(op->dialog,"SUBSCRIBE"):NULL; /*cannot create request if dialog not set yet*/
@@ -601,7 +601,7 @@ int sal_unsubscribe(SalOp *op){
 	}
 	belle_sip_message_add_header(BELLE_SIP_MESSAGE(req),belle_sip_header_create("Event","Presence"));
 	belle_sip_message_add_header(BELLE_SIP_MESSAGE(req),BELLE_SIP_HEADER(belle_sip_header_expires_create(0)));
-	return sal_op_send_request_with_contact(op,req);
+	return sal_op_send_request(op,req);
 }
 int sal_subscribe_accept(SalOp *op){
 	belle_sip_request_t* req=belle_sip_transaction_get_request(BELLE_SIP_TRANSACTION(op->pending_server_trans));
diff --git a/coreapi/bellesip_sal/sal_op_registration.c b/coreapi/bellesip_sal/sal_op_registration.c
index ea1eb6c82..a8ac7e874 100644
--- a/coreapi/bellesip_sal/sal_op_registration.c
+++ b/coreapi/bellesip_sal/sal_op_registration.c
@@ -119,7 +119,7 @@ static int send_register_request_with_expires(SalOp* op, belle_sip_request_t* re
 		belle_sip_message_add_header(BELLE_SIP_MESSAGE(request),BELLE_SIP_HEADER(expires_header=belle_sip_header_expires_new()));
 	}
 	if (expires_header) belle_sip_header_expires_set_expires(expires_header,expires);
-	return sal_op_send_request_with_contact(op,request);
+	return sal_op_send_request(op,request);
 }
 
 
diff --git a/coreapi/proxy.c b/coreapi/proxy.c
index 92df31eed..47a7cdd57 100644
--- a/coreapi/proxy.c
+++ b/coreapi/proxy.c
@@ -255,7 +255,7 @@ void linphone_proxy_config_apply(LinphoneProxyConfig *obj,LinphoneCore *lc)
 	obj->lc=lc;
 	linphone_proxy_config_done(obj);
 }
-#ifndef USE_BELLESIP
+
 static char *guess_contact_for_register(LinphoneProxyConfig *obj){
 	LinphoneAddress *proxy=linphone_address_new(obj->reg_proxy);
 	char *ret=NULL;
@@ -278,6 +278,12 @@ static char *guess_contact_for_register(LinphoneProxyConfig *obj){
 			localport = linphone_upnp_context_get_external_port(obj->lc->upnp);
 		}
 #endif //BUILD_UPNP 		
+#ifndef USE_BELLESIP
+	else {
+		linphone_address_destroy(contact);
+		return NULL;
+	}
+#endif
 		if(localip == NULL) {
 			localip = localip_tmp;
 			linphone_core_get_local_ip(obj->lc,host,localip_tmp);
@@ -288,7 +294,7 @@ static char *guess_contact_for_register(LinphoneProxyConfig *obj){
 		linphone_address_set_port_int(contact,localport);
 		linphone_address_set_domain(contact,localip);
 		linphone_address_set_display_name(contact,NULL);
-		
+
 		linphone_core_get_sip_transports(obj->lc,&tr);
 		if (tr.udp_port <= 0) {
 			if (tr.tcp_port>0) {
@@ -297,6 +303,7 @@ static char *guess_contact_for_register(LinphoneProxyConfig *obj){
 				sal_address_set_param(contact,"transport","tls");
 			}
 		}
+
 		tmp=linphone_address_as_string_uri_only(contact);
 		if (obj->contact_params)
 			ret=ms_strdup_printf("<%s;%s>",tmp,obj->contact_params);
@@ -307,20 +314,17 @@ static char *guess_contact_for_register(LinphoneProxyConfig *obj){
 	linphone_address_destroy (proxy);
 	return ret;
 }
-#endif
+
 static void linphone_proxy_config_register(LinphoneProxyConfig *obj){
 	if (obj->reg_sendregister){
-#ifndef USE_BELLESIP
 		char *contact;
-#endif
 		if (obj->op)
 			sal_op_release(obj->op);
 		obj->op=sal_op_new(obj->lc->sal);
-#ifndef USE_BELLESIP /*contact is automatically guessed by belle-sip*/
-		contact=guess_contact_for_register(obj);
-		sal_op_set_contact(obj->op,contact);
-		ms_free(contact);
-#endif
+		if ((contact=guess_contact_for_register(obj))) {
+			sal_op_set_contact(obj->op,contact);
+			ms_free(contact);
+		}
 		sal_op_set_user_pointer(obj->op,obj);
 		if (sal_register(obj->op,obj->reg_proxy,obj->reg_identity,obj->expires)==0) {
 			linphone_proxy_config_set_state(obj,LinphoneRegistrationProgress,"Registration in progress");