diff --git a/CEP/DP3/AOFlagger/src/gui/imagewidget.cpp b/CEP/DP3/AOFlagger/src/gui/imagewidget.cpp
index 5aec1e49c1eff6a2baf8dbb27e318a227757d1f8..cfccd90d6ce97c33552f5c226890c6e9533d2dd0 100644
--- a/CEP/DP3/AOFlagger/src/gui/imagewidget.cpp
+++ b/CEP/DP3/AOFlagger/src/gui/imagewidget.cpp
@@ -324,8 +324,8 @@ void ImageWidget::update(Cairo::RefPtr<Cairo::Context> cairo, unsigned width, un
 		_highlightConfig->Execute(image, highlightMask, true, 10.0);
 	}
 	const bool
-		originalActive = _showOriginalMask && _originalMask != 0,
-		altActive = _showAlternativeMask && _alternativeMask != 0;
+		originalActive = _showOriginalMask && originalMask != 0,
+		altActive = _showAlternativeMask && alternativeMask != 0;
 	for(unsigned long y=startY;y<endY;++y) {
 		guint8* rowpointer = data + rowStride * (endY - y - 1);
 		for(unsigned long x=startX;x<endX;++x) {
@@ -333,9 +333,9 @@ void ImageWidget::update(Cairo::RefPtr<Cairo::Context> cairo, unsigned width, un
 			char r,g,b,a;
 			if(_highlighting && highlightMask->Value(x, y) != 0) {
 				r = 255; g = 0; b = 0; a = 255;
-			} else if(originalActive && _originalMask->Value(x, y)) {
+			} else if(originalActive && originalMask->Value(x, y)) {
 				r = 255; g = 0; b = 255; a = 255;
-			} else if(altActive && _alternativeMask->Value(x, y)) {
+			} else if(altActive && alternativeMask->Value(x, y)) {
 				r = 255; g = 255; b = 0; a = 255;
 			} else {
 				num_t val = image->Value(x, y);
diff --git a/CEP/DP3/AOFlagger/src/gui/mswindow.cpp b/CEP/DP3/AOFlagger/src/gui/mswindow.cpp
index 7d59aa57e8c77872ba242dc2dd55ba4f52b52f68..29ceafdd567196a8521bc2633012adfd1e90d016 100644
--- a/CEP/DP3/AOFlagger/src/gui/mswindow.cpp
+++ b/CEP/DP3/AOFlagger/src/gui/mswindow.cpp
@@ -1087,20 +1087,25 @@ void MSWindow::onShowStats()
 			original = _timeFrequencyWidget.OriginalMask(),
 			alternative = _timeFrequencyWidget.AlternativeMask();
 		Mask2DPtr
-			intersect = Mask2D::CreateCopy(original);
-		intersect->Intersect(alternative);
-		unsigned intCount = intersect->GetCount<true>();
-		if(intCount != 0)
+			intersect;
+		if(original != 0 && alternative != 0)
 		{
-			if(!original->Equals(alternative))
+			intersect = Mask2D::CreateCopy(original);
+			intersect->Intersect(alternative);
+			
+			unsigned intCount = intersect->GetCount<true>();
+			if(intCount != 0)
 			{
-				s << "Overlap between original and alternative: " << TimeFrequencyStatistics::FormatRatio((double) intCount / ((double) (original->Width() * original->Height()))) << "\n"
-				<< "(relative to alternative flags: " << TimeFrequencyStatistics::FormatRatio((double) intCount / ((double) (alternative->GetCount<true>()))) << ")\n";
-				
+				if(!original->Equals(alternative))
+				{
+					s << "Overlap between original and alternative: " << TimeFrequencyStatistics::FormatRatio((double) intCount / ((double) (original->Width() * original->Height()))) << "\n"
+					<< "(relative to alternative flags: " << TimeFrequencyStatistics::FormatRatio((double) intCount / ((double) (alternative->GetCount<true>()))) << ")\n";
+					
+				}
 			}
 		}
 		
-		Image2DCPtr powerImg = activeData.GetSingleImage();	
+		Image2DCPtr powerImg = activeData.GetSingleImage();
 		Mask2DCPtr mask = activeData.GetSingleMask();
 		double power = 0.0;
 		for(unsigned y=0;y<powerImg->Height();++y)
@@ -1113,9 +1118,7 @@ void MSWindow::onShowStats()
 				}
 			}
 		}
-		s
-			<< "Total unflagged power: " << power << "\n";
-
+		s << "Total unflagged power: " << power << "\n";
 		Gtk::MessageDialog dialog(*this, s.str(), false, Gtk::MESSAGE_INFO);
 		dialog.run();
 	}