diff --git a/src/net/java/sip/communicator/impl/neomedia/RTPConnectorInputStream.java b/src/net/java/sip/communicator/impl/neomedia/RTPConnectorInputStream.java
index f8f2f696b..917538c22 100755
--- a/src/net/java/sip/communicator/impl/neomedia/RTPConnectorInputStream.java
+++ b/src/net/java/sip/communicator/impl/neomedia/RTPConnectorInputStream.java
@@ -27,10 +27,15 @@ public class RTPConnectorInputStream
      */
     private static final Object[] EMPTY_CONTROLS = new Object[0];
 
+    /**
+     * The size of the buffers receiving packets coming from network.
+     */
+    private static final int PACKET_RECEIVE_BUFFER = 4000;
+
     /**
      * Packet receive buffer
      */
-    private final byte[] buffer = new byte[65535];
+    private final byte[] buffer = new byte[PACKET_RECEIVE_BUFFER];
 
     /**
      * Whether this stream is closed. Used to control the termination of worker
@@ -222,7 +227,8 @@ public void run()
     {
         while (!closed)
         {
-            DatagramPacket p = new DatagramPacket(buffer, 0, 65535);
+            DatagramPacket p = new DatagramPacket(
+                buffer, 0, PACKET_RECEIVE_BUFFER);
 
             try
             {
diff --git a/src/net/java/sip/communicator/impl/neomedia/RawPacket.java b/src/net/java/sip/communicator/impl/neomedia/RawPacket.java
index 7ec773f99..e13309003 100755
--- a/src/net/java/sip/communicator/impl/neomedia/RawPacket.java
+++ b/src/net/java/sip/communicator/impl/neomedia/RawPacket.java
@@ -330,7 +330,8 @@ public void setCsrcList(long[] newCsrcList)
                                     | newCsrcCount);
 
         this.buffer = newBuffer;
-        this.length = newBuffer.length - offset;
+        this.length = payloadOffsetForNewBuff + oldBuffer.length
+                - payloadOffsetForOldBuff - offset;
     }
 
     /**
@@ -582,9 +583,10 @@ public void addExtension(byte[] extBuff, int newExtensionLen)
         //now copy the payload
         System.arraycopy(buffer, bufferOffset,
             newBuffer, newBufferOffset, getPayloadLength());
+        newBufferOffset += getPayloadLength();
 
         buffer = newBuffer;
-        this.length = newBuffLen - offset;
+        this.length = newBufferOffset - offset;
     }
 
     /**
diff --git a/src/net/java/sip/communicator/impl/protocol/sip/SipStackSharing.java b/src/net/java/sip/communicator/impl/protocol/sip/SipStackSharing.java
index 485c0609c..42415dfd4 100644
--- a/src/net/java/sip/communicator/impl/protocol/sip/SipStackSharing.java
+++ b/src/net/java/sip/communicator/impl/protocol/sip/SipStackSharing.java
@@ -656,6 +656,12 @@ public void processResponse(ResponseEvent event)
                             + event.getResponse().getStatusCode()
                             + " " + event.getResponse().getReasonPhrase());
 
+            if(transaction == null)
+            {
+                logger.warn("Transaction is null, probably already expired!");
+                return;
+            }
+
             ProtocolProviderServiceSipImpl service
                 = getServiceData(transaction);
             if (service != null)