diff --git a/src/org/hwo/ByteArrayHexlifier.java b/src/org/hwo/ByteArrayHexlifier.java
index 11bf74f..dc8be67 100644
--- a/src/org/hwo/ByteArrayHexlifier.java
+++ b/src/org/hwo/ByteArrayHexlifier.java
@@ -51,8 +51,6 @@ public class ByteArrayHexlifier {
 			{
 				buffer[i] = (byte)((source[2*i] - '0')<<4);
 			}
-
-			buffer[i] <<= 4;
 			
 			if ((source[(2*i)+1] >= 'A')&&(source[(2*i)+1] <= 'F'))
 			{
diff --git a/src/org/hwo/ChkSum.java b/src/org/hwo/ChkSum.java
index 5934e05..1edb4a7 100644
--- a/src/org/hwo/ChkSum.java
+++ b/src/org/hwo/ChkSum.java
@@ -2,6 +2,8 @@ package org.hwo;
 
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
+import static org.hwo.logging.Logging.*;
+import static org.hwo.logging.LogLevel.*;
 
 public class ChkSum {
 
@@ -19,6 +21,7 @@ public class ChkSum {
 		{
 			sum += buffer[n];
 			xor ^= buffer[n];
+			//log(DEBUG,"CHKSUM: 0x%02x [ 0x%02x, 0x%02x ]",buffer[n],sum,xor);
 		}
 		
 		byte[] t = new byte[12];
diff --git a/src/org/hwo/io/NewSerialPort/NewSerialPort.java b/src/org/hwo/io/NewSerialPort/NewSerialPort.java
index 24f81cb..661db45 100644
--- a/src/org/hwo/io/NewSerialPort/NewSerialPort.java
+++ b/src/org/hwo/io/NewSerialPort/NewSerialPort.java
@@ -245,11 +245,11 @@ public class NewSerialPort {
 	private static native synchronized int nsp_setup_handshake(long nsp,int handshake);
 	private static native synchronized int nsp_setup_timeout(long nsp,int timeout);
 	
-	private static native synchronized int nsp_open(long nsp);
-	private static native synchronized int nsp_close(long nsp);	
+	private static native int nsp_open(long nsp);
+	private static native int nsp_close(long nsp);	
 	
-	private static native synchronized int nsp_read(long nsp);
-	private static native synchronized int nsp_write(long nsp,int ch);
+	private static native int nsp_read(long nsp);
+	private static native int nsp_write(long nsp,int ch);
 	
 	static {
 		NativeLoader.loadLibrary("nsp");
@@ -267,7 +267,6 @@ public class NewSerialPort {
 			if (ch < 0){
 				if (ch == nsp_RET_TIMEOUT)
 					return -1;
-				NewSerialPort.this.close();
 				throw new IOException(String.format("nsp_read()=%d", ch));
 			};
 			return ch;
@@ -285,7 +284,6 @@ public class NewSerialPort {
 
 			r = nsp_write(nsp, arg0);
 			if (r<0){
-				NewSerialPort.this.close();
 				throw new IOException(String.format("nsp_write()=%d", r));
 			}
 		}