diff --git a/build.gradle b/build.gradle
index 164c67768..de25608b5 100644
--- a/build.gradle
+++ b/build.gradle
@@ -214,6 +214,12 @@ subprojects {
 	}
 }
 
+subprojects*.jar {
+   manifest {
+       from sharedManifest
+   }
+}
+
 def getGitCommit() {
 	def dotGit = new File("$projectDir/.git")
 	if (!dotGit.isDirectory()) return 'non-git build'
diff --git a/smack-core/src/main/java/org/jivesoftware/smack/sasl/SASLError.java b/smack-core/src/main/java/org/jivesoftware/smack/sasl/SASLError.java
index b066ec541..ef8b72e16 100644
--- a/smack-core/src/main/java/org/jivesoftware/smack/sasl/SASLError.java
+++ b/smack-core/src/main/java/org/jivesoftware/smack/sasl/SASLError.java
@@ -29,6 +29,7 @@ public enum SASLError {
     invalid_authzid,
     invalid_mechanism,
     malformed_request,
+    mechanism_too_weak,
     not_authorized,
     temporary_auth_failure;
 
diff --git a/smack-extensions/src/main/java/org/jivesoftware/smackx/address/MultipleRecipientManager.java b/smack-extensions/src/main/java/org/jivesoftware/smackx/address/MultipleRecipientManager.java
index 00e1e653a..8a0bc779a 100644
--- a/smack-extensions/src/main/java/org/jivesoftware/smackx/address/MultipleRecipientManager.java
+++ b/smack-extensions/src/main/java/org/jivesoftware/smackx/address/MultipleRecipientManager.java
@@ -35,6 +35,8 @@ import org.jxmpp.util.XmppStringUtils;
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 
 /**
  * A MultipleRecipientManager allows to send packets to multiple recipients by making use of
@@ -44,7 +46,9 @@ import java.util.List;
  * @author Gaston Dombiak
  */
 public class MultipleRecipientManager {
-    
+
+    private static final Logger LOGGER = Logger.getLogger(MultipleRecipientManager.class.getName());
+
     /**
      * Create a cache to hold the 100 most recently accessed elements for a period of
      * 24 hours.
@@ -204,7 +208,7 @@ public class MultipleRecipientManager {
      */
     public static MultipleRecipientInfo getMultipleRecipientInfo(Packet packet) {
         MultipleAddresses extension = (MultipleAddresses) packet
-                .getExtension("addresses", "http://jabber.org/protocol/address");
+                .getExtension(MultipleAddresses.ELEMENT, MultipleAddresses.NAMESPACE);
         return extension == null ? null : new MultipleRecipientInfo(extension);
     }
 
@@ -294,34 +298,37 @@ public class MultipleRecipientManager {
         String serviceName = connection.getServiceName();
         String serviceAddress = (String) services.get(serviceName);
         if (serviceAddress == null) {
-            synchronized (services) {
-                serviceAddress = (String) services.get(serviceName);
-                if (serviceAddress == null) {
-
-                    // Send the disco packet to the server itself
-                    DiscoverInfo info = ServiceDiscoveryManager.getInstanceFor(connection).discoverInfo(
-                                    serviceName);
-                    // Check if the server supports JEP-33
-                    if (info.containsFeature("http://jabber.org/protocol/address")) {
+            ServiceDiscoveryManager sdm = ServiceDiscoveryManager.getInstanceFor(connection);
+            // Send the disco packet to the server itself
+            DiscoverInfo info = sdm.discoverInfo(serviceName);
+            // Check if the server supports XEP-33
+            if (info.containsFeature(MultipleAddresses.NAMESPACE)) {
+                serviceAddress = serviceName;
+            }
+            else {
+                // Get the disco items and send the disco packet to each server item
+                DiscoverItems items = sdm.discoverItems(serviceName);
+                for (DiscoverItems.Item item : items.getItems()) {
+                    try {
+                        info = sdm.discoverInfo(item.getEntityID(), item.getNode());
+                    }
+                    catch (XMPPErrorException|NoResponseException e) {
+                        // Don't throw this exceptions if one of the server's items fail
+                        LOGGER.log(Level.WARNING,
+                                        "Exception while discovering info of " + item.getEntityID()
+                                                        + " node: " + item.getNode(), e);
+                        continue;
+                    }
+                    if (info.containsFeature(MultipleAddresses.NAMESPACE)) {
                         serviceAddress = serviceName;
+                        break;
                     }
-                    else {
-                        // Get the disco items and send the disco packet to each server item
-                        DiscoverItems items = ServiceDiscoveryManager.getInstanceFor(connection).discoverItems(
-                                        serviceName);
-                        for (DiscoverItems.Item item : items.getItems()) {
-                            info = ServiceDiscoveryManager.getInstanceFor(connection).discoverInfo(
-                                            item.getEntityID(), item.getNode());
-                            if (info.containsFeature("http://jabber.org/protocol/address")) {
-                                serviceAddress = serviceName;
-                                break;
-                            }
-                        }
-                    }
-                    // Cache the discovered information
-                    services.put(serviceName, serviceAddress == null ? "" : serviceAddress);
                 }
             }
+            // Use the empty string to indicate that no service is known for this connection
+            serviceAddress = serviceAddress == null ? "" : serviceAddress;
+            // Cache the discovered information
+            services.put(serviceName, serviceAddress);
         }
 
         return "".equals(serviceAddress) ? null : serviceAddress;
diff --git a/smack-extensions/src/main/java/org/jivesoftware/smackx/address/packet/MultipleAddresses.java b/smack-extensions/src/main/java/org/jivesoftware/smackx/address/packet/MultipleAddresses.java
index ea265985f..04362d024 100644
--- a/smack-extensions/src/main/java/org/jivesoftware/smackx/address/packet/MultipleAddresses.java
+++ b/smack-extensions/src/main/java/org/jivesoftware/smackx/address/packet/MultipleAddresses.java
@@ -30,6 +30,9 @@ import java.util.List;
  */
 public class MultipleAddresses implements PacketExtension {
 
+    public static final String NAMESPACE = "http://jabber.org/protocol/address";
+    public static final String ELEMENT = "addresses";
+
     public static final String BCC = "bcc";
     public static final String CC = "cc";
     public static final String NO_REPLY = "noreply";
@@ -94,17 +97,17 @@ public class MultipleAddresses implements PacketExtension {
     }
 
     public String getElementName() {
-        return "addresses";
+        return ELEMENT;
     }
 
     public String getNamespace() {
-        return "http://jabber.org/protocol/address";
+        return NAMESPACE;
     }
 
     public String toXML() {
         StringBuilder buf = new StringBuilder();
         buf.append("<").append(getElementName());
-        buf.append(" xmlns=\"").append(getNamespace()).append("\">");
+        buf.append(" xmlns=\"").append(NAMESPACE).append("\">");
         // Loop through all the addresses and append them to the string buffer
         for (Iterator<Address> i = addresses.iterator(); i.hasNext();) {
             Address address = (Address) i.next();