diff --git a/source/Components/AvalonDock/Controls/DragService.cs b/source/Components/AvalonDock/Controls/DragService.cs
index 0b7ca91a..d08f8e34 100644
--- a/source/Components/AvalonDock/Controls/DragService.cs
+++ b/source/Components/AvalonDock/Controls/DragService.cs
@@ -1,4 +1,4 @@
-/************************************************************************
+/************************************************************************
    AvalonDock
 
    Copyright (C) 2007-2013 Xceed Software Inc.
@@ -85,13 +85,14 @@ public DragService(LayoutFloatingWindowControl floatingWindow)
 		internal void UpdateMouseLocation(Point dragPosition)
 		{
 			////var floatingWindowModel = _floatingWindow.Model as LayoutFloatingWindow;
+			// TODO - pass in without DPI adjustment, screen co-ords, adjust inside the target window
 
-			var newHost = _overlayWindowHosts.FirstOrDefault(oh => oh.HitTest(dragPosition));
+			var newHost = _overlayWindowHosts.FirstOrDefault(oh => oh.HitTestScreen(dragPosition));
 
 			if (_currentHost != null || _currentHost != newHost)
 			{
 				//is mouse still inside current overlay window host?
-				if ((_currentHost != null && !_currentHost.HitTest(dragPosition)) ||
+				if ((_currentHost != null && !_currentHost.HitTestScreen(dragPosition)) ||
 					_currentHost != newHost)
 				{
 					//esit drop target
@@ -125,7 +126,7 @@ internal void UpdateMouseLocation(Point dragPosition)
 				return;
 
 			if (_currentDropTarget != null &&
-				!_currentDropTarget.HitTest(dragPosition))
+				!_currentDropTarget.HitTestScreen(dragPosition))
 			{
 				_currentWindow.DragLeave(_currentDropTarget);
 				_currentDropTarget = null;
@@ -134,8 +135,9 @@ internal void UpdateMouseLocation(Point dragPosition)
 			List<IDropArea> areasToRemove = new List<IDropArea>();
 			_currentWindowAreas.ForEach(a =>
 			{
+				
 				//is mouse still inside this area?
-				if (!a.DetectionRect.Contains(dragPosition))
+				if (!a.DetectionRect.Contains(a.TransformToDeviceDPI(dragPosition)))
 				{
 					_currentWindow.DragLeave(a);
 					areasToRemove.Add(a);
@@ -146,7 +148,7 @@ internal void UpdateMouseLocation(Point dragPosition)
 				_currentWindowAreas.Remove(a));
 
 			var areasToAdd =
-				_currentHost.GetDropAreas(_floatingWindow).Where(cw => !_currentWindowAreas.Contains(cw) && cw.DetectionRect.Contains(dragPosition)).ToList();
+				_currentHost.GetDropAreas(_floatingWindow).Where(cw => !_currentWindowAreas.Contains(cw) && cw.DetectionRect.Contains(cw.TransformToDeviceDPI(dragPosition))).ToList();
 
 			_currentWindowAreas.AddRange(areasToAdd);
 
@@ -160,7 +162,7 @@ internal void UpdateMouseLocation(Point dragPosition)
 					if (_currentDropTarget != null)
 						return;
 
-					_currentDropTarget = _currentWindow.GetTargets().FirstOrDefault(dt => dt.HitTest(dragPosition));
+					_currentDropTarget = _currentWindow.GetTargets().FirstOrDefault(dt => dt.HitTestScreen(dragPosition));
 
 					if (_currentDropTarget != null)
 					{
@@ -185,6 +187,7 @@ internal void UpdateMouseLocation(Point dragPosition)
 		/// is docked into a new visual tree position).</param>
 		internal void Drop(Point dropLocation, out bool dropHandled)
 		{
+			// TODO - pass in without DPI adjustment, screen co-ords, adjust inside the target window
 			dropHandled = false;
 
 			UpdateMouseLocation(dropLocation);
diff --git a/source/Components/AvalonDock/Controls/DropArea.cs b/source/Components/AvalonDock/Controls/DropArea.cs
index 12e8ab80..6d90ca5a 100644
--- a/source/Components/AvalonDock/Controls/DropArea.cs
+++ b/source/Components/AvalonDock/Controls/DropArea.cs
@@ -1,4 +1,4 @@
-/************************************************************************
+/************************************************************************
    AvalonDock
 
    Copyright (C) 2007-2013 Xceed Software Inc.
@@ -36,6 +36,8 @@ public interface IDropArea
 
 		/// <summary> Gets the type of drop area for this drop target.</summary>
 		DropAreaType Type { get; }
+
+		Point TransformToDeviceDPI(Point dragPosition);
 	}
 
 	/// <inheritdoc />
@@ -70,6 +72,11 @@ internal DropArea(T areaElement, DropAreaType type)
 		/// <inheritdoc />
 		public DropAreaType Type { get; }
 
+		public Point TransformToDeviceDPI(Point dragPosition)
+		{
+			return AreaElement.TransformToDeviceDPI(dragPosition);
+		}
+
 		#endregion IDropArea
 
 		#region Properties
diff --git a/source/Components/AvalonDock/Controls/DropTarget.cs b/source/Components/AvalonDock/Controls/DropTarget.cs
index c1c31ca3..26fa86ed 100644
--- a/source/Components/AvalonDock/Controls/DropTarget.cs
+++ b/source/Components/AvalonDock/Controls/DropTarget.cs
@@ -1,4 +1,4 @@
-/************************************************************************
+/************************************************************************
    AvalonDock
 
    Copyright (C) 2007-2013 Xceed Software Inc.
@@ -106,6 +106,11 @@ protected virtual void Drop(LayoutDocumentFloatingWindow floatingWindow)
 
 		#region Public Methods
 
+		public bool HitTestScreen(Point dragPoint)
+		{
+			return HitTest(_targetElement.TransformToDeviceDPI(dragPoint));
+		}
+
 		public void Drop(LayoutFloatingWindow floatingWindow)
 		{
 			var root = floatingWindow.Root;
diff --git a/source/Components/AvalonDock/Controls/IDropTarget.cs b/source/Components/AvalonDock/Controls/IDropTarget.cs
index 6a3ed90d..32e4df9b 100644
--- a/source/Components/AvalonDock/Controls/IDropTarget.cs
+++ b/source/Components/AvalonDock/Controls/IDropTarget.cs
@@ -1,4 +1,4 @@
-/************************************************************************
+/************************************************************************
    AvalonDock
 
    Copyright (C) 2007-2013 Xceed Software Inc.
@@ -48,7 +48,7 @@ internal interface IDropTarget
 		/// <summary>Determines whether the <paramref name="dragPoint"/> is part of this drop target or not.</summary>
 		/// <param name="dragPoint">The point to test.</param>
 		/// <returns><c>true</c> if it is inside the target.</returns>
-		bool HitTest(Point dragPoint);
+		bool HitTestScreen(Point dragPoint);
 
 		/// <summary>
 		/// Method is invoked to complete a drag & drop operation with a (new) docking position
diff --git a/source/Components/AvalonDock/Controls/IOverlayWindowHost.cs b/source/Components/AvalonDock/Controls/IOverlayWindowHost.cs
index 2d3ca146..effded0f 100644
--- a/source/Components/AvalonDock/Controls/IOverlayWindowHost.cs
+++ b/source/Components/AvalonDock/Controls/IOverlayWindowHost.cs
@@ -1,4 +1,4 @@
-/************************************************************************
+/************************************************************************
    AvalonDock
 
    Copyright (C) 2007-2013 Xceed Software Inc.
@@ -36,7 +36,7 @@ internal interface IOverlayWindowHost
 		/// </summary>
 		/// <param name="dragPoint">The point to test.</param>
 		/// <returns><c>true</c> if inside window, otherwise <c>false</c>.</returns>
-		bool HitTest(Point dragPoint);
+		bool HitTestScreen(Point dragPoint);
 
 		/// <summary>
 		/// Is invoked by the <see cref="DragService"/> of a <see cref="LayoutFloatingWindowControl"/>
diff --git a/source/Components/AvalonDock/Controls/LayoutAnchorableFloatingWindowControl.cs b/source/Components/AvalonDock/Controls/LayoutAnchorableFloatingWindowControl.cs
index a32aa039..73c3aa3c 100644
--- a/source/Components/AvalonDock/Controls/LayoutAnchorableFloatingWindowControl.cs
+++ b/source/Components/AvalonDock/Controls/LayoutAnchorableFloatingWindowControl.cs
@@ -1,4 +1,4 @@
-/************************************************************************
+/************************************************************************
    AvalonDock
 
    Copyright (C) 2007-2013 Xceed Software Inc.
@@ -140,7 +140,12 @@ public override void DisableBindings()
 
 		#region IOverlayWindowHost
 
-		bool IOverlayWindowHost.HitTest(Point dragPoint)
+		bool IOverlayWindowHost.HitTestScreen(Point dragPoint)
+		{
+			return HitTest(this.TransformToDeviceDPI(dragPoint));
+		}
+
+		bool HitTest(Point dragPoint)
 		{
 			var detectionRect = new Rect(this.PointToScreenDPIWithoutFlowDirection(new Point()), this.TransformActualSizeToAncestor());
 			return detectionRect.Contains(dragPoint);
@@ -151,12 +156,13 @@ void IOverlayWindowHost.HideOverlayWindow()
 			_dropAreas = null;
 			_overlayWindow.Owner = null;
 			_overlayWindow.HideDropTargets();
+			_overlayWindow.Close();
+			_overlayWindow = null;
 		}
 
 		IOverlayWindow IOverlayWindowHost.ShowOverlayWindow(LayoutFloatingWindowControl draggingWindow)
 		{
 			CreateOverlayWindow();
-			_overlayWindow.Owner = draggingWindow;
 			_overlayWindow.EnableDropTargets();
 			_overlayWindow.Show();
 			return _overlayWindow;
@@ -292,6 +298,7 @@ private void _model_IsVisibleChanged(object sender, EventArgs e)
 		private void CreateOverlayWindow()
 		{
 			if (_overlayWindow == null) _overlayWindow = new OverlayWindow(this);
+			_overlayWindow.Owner = Window.GetWindow(this);
 			var rectWindow = new Rect(this.PointToScreenDPIWithoutFlowDirection(new Point()), this.TransformActualSizeToAncestor());
 			_overlayWindow.Left = rectWindow.Left;
 			_overlayWindow.Top = rectWindow.Top;
diff --git a/source/Components/AvalonDock/Controls/LayoutDocumentFloatingWindowControl.cs b/source/Components/AvalonDock/Controls/LayoutDocumentFloatingWindowControl.cs
index 8cb81a9d..db93a0f1 100644
--- a/source/Components/AvalonDock/Controls/LayoutDocumentFloatingWindowControl.cs
+++ b/source/Components/AvalonDock/Controls/LayoutDocumentFloatingWindowControl.cs
@@ -210,7 +210,12 @@ protected override void OnClosing(System.ComponentModel.CancelEventArgs e)
 			base.OnClosing(e);
 		}
 
-		bool IOverlayWindowHost.HitTest(Point dragPoint)
+		bool IOverlayWindowHost.HitTestScreen(Point dragPoint)
+		{
+			return HitTest(this.TransformToDeviceDPI(dragPoint));
+		}
+
+		bool HitTest(Point dragPoint)
 		{
 			var detectionRect = new Rect(this.PointToScreenDPIWithoutFlowDirection(new Point()), this.TransformActualSizeToAncestor());
 			return detectionRect.Contains(dragPoint);
@@ -223,6 +228,7 @@ bool IOverlayWindowHost.HitTest(Point dragPoint)
 		private void CreateOverlayWindow()
 		{
 			if (_overlayWindow == null) _overlayWindow = new OverlayWindow(this);
+			_overlayWindow.Owner = Window.GetWindow(this);
 			var rectWindow = new Rect(this.PointToScreenDPIWithoutFlowDirection(new Point()), this.TransformActualSizeToAncestor());
 			_overlayWindow.Left = rectWindow.Left;
 			_overlayWindow.Top = rectWindow.Top;
@@ -233,7 +239,6 @@ private void CreateOverlayWindow()
 		IOverlayWindow IOverlayWindowHost.ShowOverlayWindow(LayoutFloatingWindowControl draggingWindow)
 		{
 			CreateOverlayWindow();
-			_overlayWindow.Owner = draggingWindow;
 			_overlayWindow.EnableDropTargets();
 			_overlayWindow.Show();
 			return _overlayWindow;
@@ -244,6 +249,8 @@ public void HideOverlayWindow()
 			_dropAreas = null;
 			_overlayWindow.Owner = null;
 			_overlayWindow.HideDropTargets();
+			_overlayWindow.Close();
+			_overlayWindow = null;
 		}
 
 		public IEnumerable<IDropArea> GetDropAreas(LayoutFloatingWindowControl draggingWindow)
diff --git a/source/Components/AvalonDock/Controls/LayoutFloatingWindowControl.cs b/source/Components/AvalonDock/Controls/LayoutFloatingWindowControl.cs
index c88158a6..670aa25b 100644
--- a/source/Components/AvalonDock/Controls/LayoutFloatingWindowControl.cs
+++ b/source/Components/AvalonDock/Controls/LayoutFloatingWindowControl.cs
@@ -364,7 +364,7 @@ protected virtual IntPtr FilterMessage(IntPtr hwnd, int msg, IntPtr wParam, IntP
 
 					if (_dragService != null)
 					{
-						var mousePosition = this.TransformToDeviceDPI(Win32Helper.GetMousePosition());
+						var mousePosition = (Win32Helper.GetMousePosition());
 						_dragService.Drop(mousePosition, out var dropFlag);
 						_dragService = null;
 						SetIsDragging(false);
@@ -606,13 +606,24 @@ private void OnActivated(object sender, EventArgs e)
 			var windowHandle = new WindowInteropHelper(this).Handle;
 			var mousePosition = this.PointToScreenDPI(Mouse.GetPosition(this));
 
+			var area = this.GetScreenArea();
+
 			// BugFix Issue #6
 			// This code is initializes the drag when content (document or toolwindow) is dragged
 			// A second chance back up plan if DragDelta is not set
 			if (DragDelta == default) DragDelta = new Point(3, 3);
 			Left = mousePosition.X - DragDelta.X;                 // BugFix Issue #6
 			Top = mousePosition.Y - DragDelta.Y;
+
+			if (this.GetScreenArea().Size != area.Size) // setting the top/left co-ordinates has changed the size - this means moving to a screen with a different DPI. Recalculate mouse position based on new DPI to avoid wrong drag location
+			{
+				mousePosition = this.PointToScreenDPI(Mouse.GetPosition(this));
+				Left = mousePosition.X - DragDelta.X;
+				Top = mousePosition.Y - DragDelta.Y;
+			}
+
 			_attachDrag = false;
+			Show();
 			var lParam = new IntPtr(((int)mousePosition.X & 0xFFFF) | ((int)mousePosition.Y << 16));
 			Win32Helper.SendMessage(windowHandle, Win32Helper.WM_NCLBUTTONDOWN, new IntPtr(Win32Helper.HT_CAPTION), lParam);
 		}
@@ -657,7 +668,7 @@ private void UpdateDragPosition()
 				_dragService = new DragService(this);
 				SetIsDragging(true);
 			}
-			var mousePosition = this.TransformToDeviceDPI(Win32Helper.GetMousePosition());
+			var mousePosition = (Win32Helper.GetMousePosition());
 			_dragService.UpdateMouseLocation(mousePosition);
 		}
 
diff --git a/source/Components/AvalonDock/Controls/LayoutGridControl.cs b/source/Components/AvalonDock/Controls/LayoutGridControl.cs
index efde9b3b..cd339085 100644
--- a/source/Components/AvalonDock/Controls/LayoutGridControl.cs
+++ b/source/Components/AvalonDock/Controls/LayoutGridControl.cs
@@ -637,7 +637,7 @@ private void ShowResizerOverlayWindow(LayoutGridResizerControl splitter)
 				Left = ptTopLeftScreen.X,
 				Top = ptTopLeftScreen.Y,
 				ShowActivated = false,
-				//Owner = Window.GetWindow(this),
+				Owner = Window.GetWindow(this),
 				Content = panelHostResizer
 			};
 			_resizerWindowHost.Loaded += (s, e) => _resizerWindowHost.SetParentToMainWindowOf(this);
diff --git a/source/Components/AvalonDock/DockingManager.cs b/source/Components/AvalonDock/DockingManager.cs
index 87ae7090..7e7a6b7b 100644
--- a/source/Components/AvalonDock/DockingManager.cs
+++ b/source/Components/AvalonDock/DockingManager.cs
@@ -1408,7 +1408,12 @@ private void ClearLogicalChildrenList()
 		#region IOverlayWindowHost Interface
 
 		/// <inheritdoc/>
-		bool IOverlayWindowHost.HitTest(Point dragPoint)
+		bool IOverlayWindowHost.HitTestScreen(Point dragPoint)
+		{
+			return HitTest(this.TransformToDeviceDPI(dragPoint));
+		}
+
+		bool HitTest(Point dragPoint)
 		{
 			try
 			{
@@ -1430,7 +1435,6 @@ bool IOverlayWindowHost.HitTest(Point dragPoint)
 		IOverlayWindow IOverlayWindowHost.ShowOverlayWindow(LayoutFloatingWindowControl draggingWindow)
 		{
 			CreateOverlayWindow();
-			_overlayWindow.Owner = draggingWindow;
 			_overlayWindow.EnableDropTargets();
 			_overlayWindow.Show();
 			return _overlayWindow;
@@ -1442,6 +1446,8 @@ void IOverlayWindowHost.HideOverlayWindow()
 			_areas = null;
 			_overlayWindow.Owner = null;
 			_overlayWindow.HideDropTargets();
+			_overlayWindow.Close();
+			_overlayWindow = null;
 		}
 
 		/// <inheritdoc/>
@@ -2090,7 +2096,11 @@ private void SetupAutoHideWindow()
 		private void CreateOverlayWindow()
 		{
 			if (_overlayWindow == null)
+			{
 				_overlayWindow = new OverlayWindow(this);
+			}
+			_overlayWindow.Owner = Window.GetWindow(this);
+
 			var rectWindow = new Rect(this.PointToScreenDPIWithoutFlowDirection(new Point()), this.TransformActualSizeToAncestor());
 			_overlayWindow.Left = rectWindow.Left;
 			_overlayWindow.Top = rectWindow.Top;