Index: src/codeanticode/gsvideo/GSCapture.java
===================================================================
--- src/codeanticode/gsvideo/GSCapture.java	(revision 145)
+++ src/codeanticode/gsvideo/GSCapture.java	(working copy)
@@ -45,7 +45,7 @@
   protected boolean firstFrame = true;
   protected int captureWidth;
   protected int captureHeight;
-  protected IntBuffer capturePixels;
+  protected IntBuffer capturePixels = null;
   protected Pipeline gpipe;  
   
   public GSCapture(PApplet parent, int requestWidth, int requestHeight) {
@@ -164,14 +164,29 @@
   
   /**
    * Reads the current video frame.
+   * 
+   * This method() and invokeEvent() are now synchronized, so that invokeEvent()
+   * can't be called whilst we're busy reading. In addition, I changed it so that
+   * now an internal buffer is allocated and maintained. Problematic frame error
+   * fixed by Charl P. Botha <charlbotha.com>
    */
-  public void read() {
-    if (firstFrame) {
-      // super.init(captureWidth, captureHeight, RGB);
-      loadPixels();
-      firstFrame = false;
-    }
+  public synchronized void read() {
+    // can happen that read gets called before invokeEvent having been for
+	// the first time, i.e. capturePixels not allocated yet.
+    if (capturePixels == null)
+    	return;
+    
+    // we're going to modify pixels, documentation says we have to do this every time
+    loadPixels();
+    
+    // capturePixels is an IntBuffer (capture format is 32 bits per pixel, but depth 24)
+    // turns out pixels is a list of integers as well, so we should be ok
+    capturePixels.rewind();
+    
+    // copy webcam image into our own PImage.pixels
     capturePixels.get(pixels);
+    
+    // we have modified the pixels so we have to call this
     updatePixels();
 
     available = false;
@@ -276,14 +291,29 @@
   }
 
   /**
+   * invokeEvent() and read() are synchronized so that they can not be
+   * called simultaneously. when they were not synchronized, this caused
+   * the infamous problematic frame crash.
+   * found and fixed by Charl P. Botha <charlbotha.com>
    * @invisible
    */
-  protected void invokeEvent(int w, int h, IntBuffer buffer) {
+  protected synchronized void invokeEvent(int w, int h, IntBuffer buffer) {
     available = true;
     captureWidth = w;
     captureHeight = h;
-    capturePixels = buffer;
+    
+    // we're going to copy buffer to our own capturePixels buffer, because
+    // the capture pipeline could start filling it (before calling this
+    // handler) whilst we're still reading it in the read() method
+    if (capturePixels == null)
+    	capturePixels = IntBuffer.allocate(width*height);
 
+    // now copy from buffer to capturePixels
+    // have to rewind both buffers as put is a relative bulk operation
+    buffer.rewind();
+    capturePixels.rewind();
+    capturePixels.put(buffer);
+
     // Creates a movieEvent.
     if (captureEventMethod != null) {
       try {