diff --git a/src/megabasterd/Download.java b/src/megabasterd/Download.java
index 05d70a49d..07f28f4d2 100644
--- a/src/megabasterd/Download.java
+++ b/src/megabasterd/Download.java
@@ -62,6 +62,7 @@ public final class Download implements Transference, Runnable, SecureNotifiable
     private volatile SpeedMeter _speed_meter = null; //lazy init
     private volatile ProgressMeter _progress_meter = null; //lazy init;
     private final Object _secure_notify_lock;
+    private final Object _workers_lock;
     private boolean _notified;
     private final String _url;
     private final String _download_path;
@@ -121,6 +122,7 @@ public final class Download implements Transference, Runnable, SecureNotifiable
         _slots = slots;
         _restart = restart;
         _secure_notify_lock = new Object();
+        _workers_lock = new Object();
         _chunkworkers = new ArrayList<>();
         _partialProgressQueue = new ConcurrentLinkedQueue<>();
         _rejectedChunkIds = new ConcurrentLinkedQueue<>();
@@ -317,9 +319,12 @@ public final class Download implements Transference, Runnable, SecureNotifiable
 
             getSpeed_meter().secureNotify();
 
-            for (ChunkDownloader downloader : getChunkworkers()) {
+            synchronized (_workers_lock) {
 
-                downloader.secureNotify();
+                for (ChunkDownloader downloader : getChunkworkers()) {
+
+                    downloader.secureNotify();
+                }
             }
 
             getView().resume();
@@ -1114,7 +1119,7 @@ public final class Download implements Transference, Runnable, SecureNotifiable
 
                 getView().stop("Stopping download safely, please wait...");
 
-                synchronized (this) {
+                synchronized (_workers_lock) {
 
                     for (ChunkDownloader downloader : _chunkworkers) {
 
@@ -1122,6 +1127,8 @@ public final class Download implements Transference, Runnable, SecureNotifiable
                     }
                 }
 
+                System.out.println("stop4");
+
                 secureNotify();
             }
         }
diff --git a/src/megabasterd/DownloadView.java b/src/megabasterd/DownloadView.java
index 95c4411dc..c6eb7a1c9 100644
--- a/src/megabasterd/DownloadView.java
+++ b/src/megabasterd/DownloadView.java
@@ -354,12 +354,14 @@ public final class DownloadView extends javax.swing.JPanel implements Transferen
     private void stop_buttonActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_stop_buttonActionPerformed
 
         _download.stop();
+        System.out.println("stopped");
 
     }//GEN-LAST:event_stop_buttonActionPerformed
 
     private void pause_buttonActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_pause_buttonActionPerformed
 
         _download.pause();
+        System.out.println("paused!");
     }//GEN-LAST:event_pause_buttonActionPerformed
 
     @Override
diff --git a/src/megabasterd/MainPanel.java b/src/megabasterd/MainPanel.java
index 852bcdfc4..a6faa2647 100644
--- a/src/megabasterd/MainPanel.java
+++ b/src/megabasterd/MainPanel.java
@@ -61,7 +61,7 @@ import org.apache.http.auth.UsernamePasswordCredentials;
  */
 public final class MainPanel {
 
-    public static final String VERSION = "1.62";
+    public static final String VERSION = "1.63";
     public static final int THROTTLE_SLICE_SIZE = 16 * 1024;
     public static final int STREAMER_PORT = 1337;
     public static final int WATCHDOG_PORT = 1338;
diff --git a/src/megabasterd/Upload.java b/src/megabasterd/Upload.java
index 266aabaf1..518a72c7d 100644
--- a/src/megabasterd/Upload.java
+++ b/src/megabasterd/Upload.java
@@ -42,6 +42,7 @@ public final class Upload implements Transference, Runnable, SecureNotifiable {
     private volatile boolean _exit;
     private final int _slots;
     private final Object _secure_notify_lock;
+    private final Object _workers_lock;
     private byte[] _byte_file_key;
     private String _fatal_error;
     private volatile long _progress;
@@ -97,6 +98,7 @@ public final class Upload implements Transference, Runnable, SecureNotifiable {
         _restart = restart;
         _completion_handle = null;
         _secure_notify_lock = new Object();
+        _workers_lock = new Object();
         _chunkworkers = new ArrayList<>();
         _partialProgressQueue = new ConcurrentLinkedQueue<>();
         _rejectedChunkIds = new ConcurrentLinkedQueue<>();
@@ -494,9 +496,12 @@ public final class Upload implements Transference, Runnable, SecureNotifiable {
 
             getSpeed_meter().secureNotify();
 
-            for (ChunkUploader uploader : getChunkworkers()) {
+            synchronized (_workers_lock) {
 
-                uploader.secureNotify();
+                for (ChunkUploader uploader : getChunkworkers()) {
+
+                    uploader.secureNotify();
+                }
             }
 
             setPaused_workers(0);
@@ -988,7 +993,7 @@ public final class Upload implements Transference, Runnable, SecureNotifiable {
 
             getView().stop("Stopping upload safely, please wait...");
 
-            synchronized (this) {
+            synchronized (_workers_lock) {
 
                 for (ChunkUploader uploader : _chunkworkers) {