diff --git a/bin/classes/com/felhr/usbserial/CP2102SerialDevice.class b/bin/classes/com/felhr/usbserial/CP2102SerialDevice.class
index 883802e..01011b1 100644
Binary files a/bin/classes/com/felhr/usbserial/CP2102SerialDevice.class and b/bin/classes/com/felhr/usbserial/CP2102SerialDevice.class differ
diff --git a/bin/classes/com/felhr/usbserial/SerialBuffer.class b/bin/classes/com/felhr/usbserial/SerialBuffer.class
index 1a02572..7f91892 100644
Binary files a/bin/classes/com/felhr/usbserial/SerialBuffer.class and b/bin/classes/com/felhr/usbserial/SerialBuffer.class differ
diff --git a/bin/classes/com/felhr/usbserial/UsbSerialDevice$WorkerThread.class b/bin/classes/com/felhr/usbserial/UsbSerialDevice$WorkerThread.class
index 26b1d40..8088083 100644
Binary files a/bin/classes/com/felhr/usbserial/UsbSerialDevice$WorkerThread.class and b/bin/classes/com/felhr/usbserial/UsbSerialDevice$WorkerThread.class differ
diff --git a/bin/classes/com/felhr/usbserial/UsbSerialDevice.class b/bin/classes/com/felhr/usbserial/UsbSerialDevice.class
index 6614c50..77b28e7 100644
Binary files a/bin/classes/com/felhr/usbserial/UsbSerialDevice.class and b/bin/classes/com/felhr/usbserial/UsbSerialDevice.class differ
diff --git a/bin/usbserial.jar b/bin/usbserial.jar
index 89366d8..030a50b 100644
Binary files a/bin/usbserial.jar and b/bin/usbserial.jar differ
diff --git a/src/com/felhr/usbserial/CP2102SerialDevice.java b/src/com/felhr/usbserial/CP2102SerialDevice.java
index 5f3f317..d631686 100644
--- a/src/com/felhr/usbserial/CP2102SerialDevice.java
+++ b/src/com/felhr/usbserial/CP2102SerialDevice.java
@@ -117,7 +117,10 @@ public class CP2102SerialDevice extends UsbSerialDevice
 	@Override
 	public void close() 
 	{
-		// TODO 
+		setControlCommand(CP210x_IFC_ENABLE, CP210x_UART_DISABLE, null);
+		connection.close();
+		workerThread.stopWorkingThread();
+		listenThread.stopListenThread();
 	}
 
 	@Override
@@ -147,7 +150,7 @@ public class CP2102SerialDevice extends UsbSerialDevice
 	@Override
 	public void setParity(int parity) 
 	{
-		// TODO Auto-generated method stub
+		// TODO
 	}
 
 	@Override
@@ -181,7 +184,9 @@ public class CP2102SerialDevice extends UsbSerialDevice
 		{
 			dataLength = data.length;
 		}
-		return connection.controlTransfer(CP210x_REQTYPE_HOST2DEVICE, request, value, 0, data, dataLength, USB_TIMEOUT);
+		int response = connection.controlTransfer(CP210x_REQTYPE_HOST2DEVICE, request, value, 0, data, dataLength, USB_TIMEOUT);
+		Log.i(CLASS_ID,"Control Transfer Response: " + String.valueOf(response));
+		return response;
 	}
 
 }
diff --git a/src/com/felhr/usbserial/SerialBuffer.java b/src/com/felhr/usbserial/SerialBuffer.java
index 82fe502..378b62a 100644
--- a/src/com/felhr/usbserial/SerialBuffer.java
+++ b/src/com/felhr/usbserial/SerialBuffer.java
@@ -12,12 +12,12 @@ public class SerialBuffer
 	private Object mReadLock;
 	private Object mWriteLock;
 	
-	public SerialBuffer(Object mReadLock, Object mWriteLock)
+	public SerialBuffer()
 	{
 		writeBuffer = ByteBuffer.allocate(DEFAULT_WRITE_BUFFER_SIZE);
 		readBuffer = ByteBuffer.allocate(DEFAULT_READ_BUFFER_SIZE);
-		this.mReadLock = mReadLock;
-		this.mWriteLock = mWriteLock;
+		this.mReadLock =  new Object();
+		this.mWriteLock = new Object();
 	}
 	
 	public void putWriteBuffer(byte[] data)
diff --git a/src/com/felhr/usbserial/UsbSerialDevice.java b/src/com/felhr/usbserial/UsbSerialDevice.java
index 445de2f..59931d4 100644
--- a/src/com/felhr/usbserial/UsbSerialDevice.java
+++ b/src/com/felhr/usbserial/UsbSerialDevice.java
@@ -17,8 +17,6 @@ public abstract class UsbSerialDevice implements UsbSerialInterface
 	protected final UsbDeviceConnection connection;
 	
 	protected SerialBuffer serialBuffer;
-	protected final Object readBufferLock;
-	protected final Object writeBufferLock;
 	
 	private Object objectMonitor;
 	protected ListenThread listenThread;
@@ -28,9 +26,8 @@ public abstract class UsbSerialDevice implements UsbSerialInterface
 	{
 		this.device = device;
 		this.connection = connection;
-		this.readBufferLock = new Object();
-		this.writeBufferLock = new Object();
-		serialBuffer = new SerialBuffer(readBufferLock, writeBufferLock);
+		this.objectMonitor = new Object();
+		serialBuffer = new SerialBuffer();
 		workerThread = new WorkerThread();
 		workerThread.start();
 	}
@@ -88,7 +85,10 @@ public abstract class UsbSerialDevice implements UsbSerialInterface
 					Log.i(CLASS_ID, "Send data length: "  + String.valueOf(pos + 1));
 					serialBuffer.clearWriteBuffer();
 				}
-				objectMonitor.notify();
+				synchronized(objectMonitor)
+				{
+					objectMonitor.notify();
+				}
 			}
 		}