diff --git a/rtengine/cplx_wavelet_level.h b/rtengine/cplx_wavelet_level.h
index a89b91af6..e8fa3bc96 100644
--- a/rtengine/cplx_wavelet_level.h
+++ b/rtengine/cplx_wavelet_level.h
@@ -298,8 +298,8 @@ namespace rtengine {
 			dstLo[(pitch*(i))] = 0.5*(srcbuffer[i] + srcbuffer[i+skip]);
 			dstHi[(pitch*(i))] = 0.5*(srcbuffer[i] - srcbuffer[i+skip]);
 		}
-		
-		for(size_t i = (srclen-skip); i < (srclen); i++) {
+		// Start the loop at max(srclen-skip,skip) to avoid buffer underrun
+		for(size_t i = max(srclen-skip,skip); i < (srclen); i++) {
 			dstLo[(pitch*(i))] = 0.5*(srcbuffer[i] + srcbuffer[i-skip]);
 			dstHi[(pitch*(i))] = 0.5*(srcbuffer[i] - srcbuffer[i-skip]);
 		}
diff --git a/rtgui/cropwindow.cc b/rtgui/cropwindow.cc
index ebc72d35d..991827bf9 100755
--- a/rtgui/cropwindow.cc
+++ b/rtgui/cropwindow.cc
@@ -108,11 +108,14 @@ CropWindow::CropWindow (ImageArea* parent, rtengine::StagedImageProcessor* ipc_,
 
     cropHandler.setCropHandlerListener (this);
     cropHandler.newImage (ipc_);
-    cropHandler.setEnabled (true);
 
     state = SNormal;
 }
 
+void CropWindow::enable() {
+    cropHandler.setEnabled (true);
+}
+
 void CropWindow::setPosition (int x, int y) {
     
     if (y<0)
diff --git a/rtgui/cropwindow.h b/rtgui/cropwindow.h
index 4676d2145..80460f188 100755
--- a/rtgui/cropwindow.h
+++ b/rtgui/cropwindow.h
@@ -120,6 +120,7 @@ class CropWindow : public LWButtonListener, public CropHandlerListener, public E
         void getPosition (int& x, int& y);
         void setSize     (int w, int h, bool norefresh=false);
         void getSize     (int& w, int& h);
+        void enable      ();
 
         void leaveNotify (GdkEventCrossing* event);
         void flawnOver   (bool isFlawnOver);
diff --git a/rtgui/imagearea.cc b/rtgui/imagearea.cc
index c310f4799..dba3d68f5 100644
--- a/rtgui/imagearea.cc
+++ b/rtgui/imagearea.cc
@@ -93,6 +93,7 @@ void ImageArea::on_resized (Gtk::Allocation& req) {
 			mainCropWindow->setPointerMotionHListener (pmhlistener);
 			mainCropWindow->setPosition (0, 0);
 			mainCropWindow->setSize (get_width(), get_height(), false);  // this execute the refresh itself
+			mainCropWindow->enable();  // start processing !
 		}
 		else {
 			mainCropWindow->setSize (get_width(), get_height());
@@ -386,6 +387,9 @@ void ImageArea::addCropWindow () {
         cw->setPosition (lastClosedX, lastClosedY);
         lastClosedX = -1;
     }
+
+    cw->enable(); // start processing!
+
     int x0,y0,w,h,wc,hc;
     mainCropWindow->getCropRectangle(x0,y0,w,h );
     cw->getCropSize(wc,hc);