Small bug fixes

src/net/java/sip/communicator/impl/protocol/jabber/OperationSetTelephonyConferencingJabberImpl.java

@@ -171,8 +171,12 @@ public void run()
         ConferenceInfoDocument lastSentConfInfo
                 = callPeerJabber.getLastConferenceInfoSent();
 
-        ConferenceInfoDocument diff
-                = getConferenceInfoDiff(lastSentConfInfo, currentConfInfo);
+        ConferenceInfoDocument diff;
+
+        if (lastSentConfInfo == null)
+            diff = currentConfInfo;
+        else
+            diff = getConferenceInfoDiff(lastSentConfInfo, currentConfInfo);
 
         if (diff != null)
         {

src/net/java/sip/communicator/service/protocol/media/AbstractOperationSetTelephonyConferencing.java

@@ -1326,7 +1326,7 @@ private boolean conferenceInfoDocumentsMatch(
             throw new IllegalArgumentException("The 'b' document needs to"
                     + "have state=full");
 
-        if (stringsMatch(a.getEntity(), b.getEntity()))
+        if (!stringsMatch(a.getEntity(), b.getEntity()))
             return false;
         else if (a.getUserCount() != b.getUserCount())
             return false;