diff --git a/src/AddIns/Misc/SearchAndReplace/Project/Commands/SearchToolbarCommands.cs b/src/AddIns/Misc/SearchAndReplace/Project/Commands/SearchToolbarCommands.cs
index 738bef2e9b..4b1366daf5 100644
--- a/src/AddIns/Misc/SearchAndReplace/Project/Commands/SearchToolbarCommands.cs
+++ b/src/AddIns/Misc/SearchAndReplace/Project/Commands/SearchToolbarCommands.cs
@@ -35,8 +35,8 @@ namespace SearchAndReplace
 		void OnKeyPress(object sender, KeyEventArgs e)
 		{
 			if (e.Key == Key.Enter) {
-				CommitSearch();
 				e.Handled = true;
+				CommitSearch();
 			}
 		}
 		
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/Caret.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/Caret.cs
index 472bb13523..cdeed6b49b 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/Caret.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/Caret.cs
@@ -5,13 +5,13 @@
 //     <version>$Revision$</version>
 // </file>
 
+using ICSharpCode.AvalonEdit.Utils;
 using System;
 using System.Diagnostics;
 using System.Windows;
 using System.Windows.Documents;
 using System.Windows.Media.TextFormatting;
 using System.Windows.Threading;
-
 using ICSharpCode.AvalonEdit.Document;
 using ICSharpCode.AvalonEdit.Rendering;
 
@@ -58,7 +58,7 @@ namespace ICSharpCode.AvalonEdit.Editing
 		
 		/// <summary>
 		/// Gets/Sets the position of the caret.
-		/// Retrieving this property will validate the visual column.
+		/// Retrieving this property will validate the visual column (which can be expensive).
 		/// Use the <see cref="Location"/> property instead if you don't need the visual column.
 		/// </summary>
 		public TextViewPosition Position {
@@ -264,7 +264,9 @@ namespace ICSharpCode.AvalonEdit.Editing
 				// then try backwards
 				newVisualColumn = visualLine.GetNextCaretPosition(position.VisualColumn + 1, LogicalDirection.Backward, CaretPositioningMode.Normal);
 			}
-			if (newVisualColumn >= 0 && newVisualColumn != position.VisualColumn) {
+			if (newVisualColumn < 0)
+				throw ThrowUtil.NoValidCaretPosition();
+			if (newVisualColumn != position.VisualColumn) {
 				int newOffset = visualLine.GetRelativeOffset(newVisualColumn) + firstDocumentLineOffset;
 				this.Position = new TextViewPosition(textView.Document.GetLocation(newOffset), newVisualColumn);
 			}
@@ -294,7 +296,9 @@ namespace ICSharpCode.AvalonEdit.Editing
 		{
 			if (textView != null) {
 				VisualLine visualLine = textView.GetOrConstructVisualLine(textView.Document.GetLineByNumber(position.Line));
-				textView.MakeVisible(CalcCaretRectangle(visualLine));
+				Rect caretRectangle = CalcCaretRectangle(visualLine);
+				caretRectangle.Inflate(30, 30); // leave at least 30 pixels distance to the view border
+				textView.MakeVisible(caretRectangle);
 			}
 		}
 		
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/CaretNavigationCommandHandler.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/CaretNavigationCommandHandler.cs
index 6d3d8b0f36..18a5717778 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/CaretNavigationCommandHandler.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/CaretNavigationCommandHandler.cs
@@ -7,6 +7,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Windows.Documents;
 using System.Windows.Input;
 using System.Windows.Media.TextFormatting;
@@ -185,9 +186,8 @@ namespace ICSharpCode.AvalonEdit.Editing
 		static void MoveCaretToStartOfLine(TextArea textArea, VisualLine visualLine)
 		{
 			int newVC = visualLine.GetNextCaretPosition(-1, LogicalDirection.Forward, CaretPositioningMode.WordStart);
-			// in empty lines (whitespace only), jump to the end
 			if (newVC < 0)
-				newVC = visualLine.VisualLength;
+				throw ThrowUtil.NoValidCaretPosition();
 			// when the caret is already at the start of the text, jump to start before whitespace
 			if (newVC == textArea.Caret.VisualColumn)
 				newVC = 0;
@@ -211,18 +211,40 @@ namespace ICSharpCode.AvalonEdit.Editing
 				SetCaretPosition(textArea, pos, visualLine.GetRelativeOffset(pos) + visualLine.FirstDocumentLine.Offset);
 			} else {
 				// move to start of next line
-				SetCaretPosition(textArea, 0, visualLine.LastDocumentLine.Offset + visualLine.LastDocumentLine.TotalLength);
+				DocumentLine nextDocumentLine = visualLine.LastDocumentLine.NextLine;
+				if (nextDocumentLine != null) {
+					VisualLine nextLine = textArea.TextView.GetOrConstructVisualLine(nextDocumentLine);
+					pos = nextLine.GetNextCaretPosition(-1, LogicalDirection.Forward, mode);
+					if (pos < 0)
+						throw ThrowUtil.NoValidCaretPosition();
+					SetCaretPosition(textArea, pos, nextLine.GetRelativeOffset(pos) + nextLine.FirstDocumentLine.Offset);
+				} else {
+					// at end of document
+					Debug.Assert(visualLine.LastDocumentLine.Offset + visualLine.LastDocumentLine.TotalLength == textArea.Document.TextLength);
+					SetCaretPosition(textArea, -1, textArea.Document.TextLength);
+				}
 			}
 		}
-
+		
 		static void MoveCaretLeft(TextArea textArea, TextViewPosition caretPosition, VisualLine visualLine, CaretPositioningMode mode)
 		{
 			int pos = visualLine.GetNextCaretPosition(caretPosition.VisualColumn, LogicalDirection.Backward, mode);
 			if (pos >= 0) {
 				SetCaretPosition(textArea, pos, visualLine.GetRelativeOffset(pos) + visualLine.FirstDocumentLine.Offset);
-			} else if (caretPosition.Line > 1) {
-				DocumentLine prevLine = textArea.Document.GetLineByNumber(caretPosition.Line - 1);
-				SetCaretPosition(textArea, -1, prevLine.Offset + prevLine.Length);
+			} else {
+				// move to end of previous line
+				DocumentLine previousDocumentLine = visualLine.FirstDocumentLine.PreviousLine;
+				if (previousDocumentLine != null) {
+					VisualLine previousLine = textArea.TextView.GetOrConstructVisualLine(previousDocumentLine);
+					pos = previousLine.GetNextCaretPosition(previousLine.VisualLength + 1, LogicalDirection.Backward, mode);
+					if (pos < 0)
+						throw ThrowUtil.NoValidCaretPosition();
+					SetCaretPosition(textArea, pos, previousLine.GetRelativeOffset(pos) + previousLine.FirstDocumentLine.Offset);
+				} else {
+					// at start of document
+					Debug.Assert(visualLine.FirstDocumentLine.Offset == 0);
+					SetCaretPosition(textArea, 0, 0);
+				}
 			}
 		}
 		#endregion
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/EditingCommandHandler.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/EditingCommandHandler.cs
index c8afb01915..737c48034f 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/EditingCommandHandler.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/EditingCommandHandler.cs
@@ -232,16 +232,6 @@ namespace ICSharpCode.AvalonEdit.Editing
 						if (textArea.Selection.IsEmpty)
 							selectingCommand.Execute(args.Parameter, textArea);
 						textArea.RemoveSelectedText();
-						if (selectingCommand == EditingCommands.SelectLeftByWord) {
-							// Special case: when Ctrl+Backspace deletes until the start of the line,
-							// also delete the previous line delimiter.
-							// This allows deleting lines that consist only of indentation using a single
-							// press on Ctrl+Backspace.
-							if (textArea.Caret.Column == 1 && textArea.Caret.VisualColumn == 0 && textArea.Caret.Line > 1) {
-								DocumentLine previousLine = textArea.Document.GetLineByNumber(textArea.Caret.Line - 1);
-								textArea.Document.Remove(previousLine.EndOffset, previousLine.DelimiterLength);
-							}
-						}
 					}
 					textArea.Caret.BringCaretToView();
 					args.Handled = true;
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Rendering/VisualLine.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Rendering/VisualLine.cs
index 4def3e5364..6140ea04ea 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Rendering/VisualLine.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Rendering/VisualLine.cs
@@ -334,7 +334,8 @@ namespace ICSharpCode.AvalonEdit.Rendering
 			if (direction == LogicalDirection.Backward) {
 				// Search Backwards:
 				// If the last element doesn't handle line borders, return the line end as caret stop
-				if (visualColumn > this.VisualLength && !elements[elements.Count-1].HandlesLineBorders) {
+				// (we don't check the mode here: we treat a line end as word start, border, etc.
+				if (visualColumn > this.VisualLength && !elements[elements.Count-1].HandlesLineBorders && HasImplicitStopAtLineEnd(mode)) {
 					return this.VisualLength;
 				}
 				// skip elements that start after or at visualColumn
@@ -350,14 +351,14 @@ namespace ICSharpCode.AvalonEdit.Rendering
 					if (pos >= 0)
 						return pos;
 				}
-				// if we've found nothing, and the first element doesn't handle line borders,
-				// return the line start as caret stop
-				if (visualColumn > 0 && !elements[0].HandlesLineBorders)
+				// If we've found nothing, and the first element doesn't handle line borders,
+				// return the line start as normal caret stop.
+				if (visualColumn > 0 && !elements[0].HandlesLineBorders && HasImplicitStopAtLineStart(mode))
 					return 0;
 			} else {
 				// Search Forwards:
 				// If the first element doesn't handle line borders, return the line start as caret stop
-				if (visualColumn < 0 && !elements[0].HandlesLineBorders)
+				if (visualColumn < 0 && !elements[0].HandlesLineBorders && HasImplicitStopAtLineStart(mode))
 					return 0;
 				// skip elements that end before or at visualColumn
 				for (i = 0; i < elements.Count; i++) {
@@ -374,11 +375,21 @@ namespace ICSharpCode.AvalonEdit.Rendering
 				}
 				// if we've found nothing, and the last element doesn't handle line borders,
 				// return the line end as caret stop
-				if (visualColumn < this.VisualLength && !elements[elements.Count-1].HandlesLineBorders)
+				if (visualColumn < this.VisualLength && !elements[elements.Count-1].HandlesLineBorders && HasImplicitStopAtLineEnd(mode))
 					return this.VisualLength;
 			}
 			// we've found nothing, return -1 and let the caret search continue in the next line
 			return -1;
 		}
+		
+		static bool HasImplicitStopAtLineStart(CaretPositioningMode mode)
+		{
+			return mode == CaretPositioningMode.Normal;
+		}
+		
+		static bool HasImplicitStopAtLineEnd(CaretPositioningMode mode)
+		{
+			return true;
+		}
 	}
 }
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Utils/NullSafeCollection.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Utils/NullSafeCollection.cs
index 0151a8c2c7..4f54f94eef 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Utils/NullSafeCollection.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Utils/NullSafeCollection.cs
@@ -13,7 +13,7 @@ namespace ICSharpCode.AvalonEdit.Utils
 	/// <summary>
 	/// A collection that cannot contain null values.
 	/// </summary>
-	public sealed class NullSafeCollection<T> : Collection<T> where T : class
+	public class NullSafeCollection<T> : Collection<T> where T : class
 	{
 		/// <inheritdoc/>
 		protected override void InsertItem(int index, T item)
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Utils/ObserveAddRemoveCollection.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Utils/ObserveAddRemoveCollection.cs
index 2f13a4f972..7e761e4210 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Utils/ObserveAddRemoveCollection.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Utils/ObserveAddRemoveCollection.cs
@@ -12,6 +12,8 @@ namespace ICSharpCode.AvalonEdit.Utils
 {
 	/// <summary>
 	/// A collection where adding and removing items causes a callback.
+	/// It is valid for the onAdd callback to throw an exception - this will prevent the new item from
+	/// being added to the collection.
 	/// </summary>
 	sealed class ObserveAddRemoveCollection<T> : Collection<T>
 	{
@@ -54,7 +56,8 @@ namespace ICSharpCode.AvalonEdit.Utils
 				if (onAdd != null)
 					onAdd(item);
 			} catch {
-				// when adding the new item fails, just remove the old one
+				// When adding the new item fails, just remove the old one
+				// (we cannot keep the old item since we already successfully called onRemove for it)
 				base.RemoveAt(index);
 				throw;
 			}
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Utils/TextUtilities.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Utils/TextUtilities.cs
index 1b626635a8..86a5b64ad9 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Utils/TextUtilities.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Utils/TextUtilities.cs
@@ -191,6 +191,11 @@ namespace ICSharpCode.AvalonEdit.Utils
 		/// <param name="mode">The mode for caret positioning.</param>
 		/// <returns>The offset of the next caret position, or -1 if there is no further caret position
 		/// in the text source.</returns>
+		/// <remarks>
+		/// This method is NOT equivalent to the actual caret movement when using VisualLine.GetNextCaretPosition.
+		/// In real caret movement, there are additional caret stops at line starts and ends. However, this method
+		/// doesn't know anything about lines: it is often called with a textSource that represents only a single VisualTextElement.
+		/// </remarks>
 		public static int GetNextCaretPosition(ITextSource textSource, int offset, LogicalDirection direction, CaretPositioningMode mode)
 		{
 			if (textSource == null)
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Utils/ThrowUtil.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Utils/ThrowUtil.cs
index 90832ea91a..a545e26285 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Utils/ThrowUtil.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Utils/ThrowUtil.cs
@@ -22,7 +22,7 @@ namespace ICSharpCode.AvalonEdit.Utils
 		/// Use this method to throw an ArgumentNullException when using parameters for base
 		/// constructor calls.
 		/// <code>
-		/// public VisualLineText(string text) : base(ThrowUtil.CheckNull(text, "text").Length)
+		/// public VisualLineText(string text) : base(ThrowUtil.CheckNotNull(text, "text").Length)
 		/// </code>
 		/// </example>
 		public static T CheckNotNull<T>(T val, string parameterName) where T : class
@@ -43,5 +43,10 @@ namespace ICSharpCode.AvalonEdit.Utils
 		{
 			throw new InvalidOperationException("Document is null");
 		}
+		
+		public static InvalidOperationException NoValidCaretPosition()
+		{
+			throw new InvalidOperationException("Could not find a valid caret position in the line");
+		}
 	}
 }
diff --git a/src/Main/Base/Project/Src/Gui/Workbench/WpfWorkbench.xaml b/src/Main/Base/Project/Src/Gui/Workbench/WpfWorkbench.xaml
index 036530e9b5..4444d51dbe 100644
--- a/src/Main/Base/Project/Src/Gui/Workbench/WpfWorkbench.xaml
+++ b/src/Main/Base/Project/Src/Gui/Workbench/WpfWorkbench.xaml
@@ -9,6 +9,6 @@
 		<Menu Name="mainMenu" DockPanel.Dock="Top"/>
 		<!-- Toolbars will be inserted here (index: 1) -->
 		<!-- Statusbar will be inserted here (index: Count-2) -->
-		<ContentControl Name="mainContent"/>
+		<ContentControl Name="mainContent" Focusable="False"/>
 	</DockPanel>
 </Window>
\ No newline at end of file