diff --git a/dart/lib/discovery/client.dart b/dart/lib/discovery/client.dart
index 87b2d47..1274f86 100644
--- a/dart/lib/discovery/client.dart
+++ b/dart/lib/discovery/client.dart
@@ -49,8 +49,8 @@
   serviceAttrs['deckid'] = presentation.deck.key;
   serviceAttrs['name'] = presentation.deck.name;
   serviceAttrs['thumbnailkey'] = presentation.deck.thumbnail.key;
+  serviceAttrs['presentationid'] = presentation.key;
   v23discovery.Service serviceInfo = new v23discovery.Service()
-    ..instanceId = presentation.key
     ..interfaceName = presentationInterfaceName
     ..instanceName = presentation.key
     ..attrs = serviceAttrs
@@ -63,7 +63,12 @@
   _advertiseCalls[presentation.key] =
       new ProxyResponseFuturePair(advertiser, advertiseResponseFuture);
 
-  await advertiseResponseFuture;
+  v23discovery.AdvertiserAdvertiseResponseParams result =
+      await advertiseResponseFuture;
+  if (result.err != null) {
+    throw result.err;
+  }
+
   log.info('Advertised ${presentation.deck.name} under ${presentation.key}.');
 }
 
@@ -119,7 +124,10 @@
   var scannerResponseFuture = scanner.ptr.scan(query, handlerStub);
   _scanCall = new ProxyResponseFuturePair(scanner, scannerResponseFuture);
 
-  await scannerResponseFuture;
+  v23discovery.ScannerScanResponseParams result = await scannerResponseFuture;
+  if (result.err != null) {
+    throw result.err;
+  }
   log.info('Scan started.');
 }
 
@@ -156,13 +164,15 @@
 }
 
 class ScanHandler extends v23discovery.ScanHandler {
+  Map<String, String> instanceIdToPresentationIdMap = new Map();
   found(v23discovery.Service s) async {
-    String key = s.instanceId;
+    String key = s.attrs['presentationid'];
+    instanceIdToPresentationIdMap[s.instanceId] = key;
     log.info('Found presentation ${s.attrs['name']} under $key.');
     // Ignore our own advertised services.
     if (_advertiseCalls.containsKey(key)) {
       log.info(
-          'Presentation ${s.attrs['name']} was advertised by this device itself, ignoring it.');
+          'Presentation ${s.attrs['name']} was advertised by us; ignoring.');
       return;
     }
 
@@ -177,8 +187,11 @@
     _onFoundEmitter.add(presentation);
   }
 
-  lost(String presentationId) {
-    // Ignore our own advertised services.
+  lost(String instanceId) {
+    String presentationId = instanceIdToPresentationIdMap[instanceId];
+    if (presentationId == null) {
+      return;
+    }
     log.info('Lost presentation $presentationId.');
     _onLostEmitter.add(presentationId);
   }
diff --git a/dart/pubspec.lock b/dart/pubspec.lock
index 8cef40f..af44d6f 100644
--- a/dart/pubspec.lock
+++ b/dart/pubspec.lock
@@ -238,7 +238,7 @@
   syncbase:
     description: syncbase
     source: hosted
-    version: "0.0.23"
+    version: "0.0.26"
   test:
     description: test
     source: hosted
@@ -258,7 +258,7 @@
   v23discovery:
     description: v23discovery
     source: hosted
-    version: "0.0.7"
+    version: "0.0.8"
   vector_math:
     description: vector_math
     source: hosted