diff --git a/ICSharpCode.NRefactory.CSharp/OutputVisitor/CodeDomConvertVisitor.cs b/ICSharpCode.NRefactory.CSharp/OutputVisitor/CodeDomConvertVisitor.cs
index 513496c699..f22091776a 100644
--- a/ICSharpCode.NRefactory.CSharp/OutputVisitor/CodeDomConvertVisitor.cs
+++ b/ICSharpCode.NRefactory.CSharp/OutputVisitor/CodeDomConvertVisitor.cs
@@ -1356,7 +1356,7 @@ namespace ICSharpCode.NRefactory.CSharp
 
 		CodeObject IAstVisitor<CodeObject>.VisitPreProcessorDirective (PreProcessorDirective preProcessorDirective)
 		{
-			return new CodeComment ("#" + preProcessorDirective.Type.ToString ().ToLower ());
+			return new CodeComment ("#" + preProcessorDirective.Type.ToString ().ToLowerInvariant ());
 		}
 		
 		CodeObject IAstVisitor<CodeObject>.VisitTypeParameterDeclaration(TypeParameterDeclaration typeParameterDeclaration)
diff --git a/ICSharpCode.NRefactory.CSharp/Refactoring/CodeActions/AddAnotherAccessorAction.cs b/ICSharpCode.NRefactory.CSharp/Refactoring/CodeActions/AddAnotherAccessorAction.cs
index b093880e66..69384a1278 100644
--- a/ICSharpCode.NRefactory.CSharp/Refactoring/CodeActions/AddAnotherAccessorAction.cs
+++ b/ICSharpCode.NRefactory.CSharp/Refactoring/CodeActions/AddAnotherAccessorAction.cs
@@ -73,7 +73,7 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 		{
 			if (pdecl.Setter.IsNull && !pdecl.Getter.IsNull) {
 				var field = RemoveBackingStoreAction.ScanGetter (context, pdecl);
-				if (field != null) 
+				if (field != null && !field.IsReadOnly && !field.IsConst) 
 					return new ExpressionStatement (new AssignmentExpression (new IdentifierExpression (field.Name), AssignmentOperatorType.Assign, new IdentifierExpression ("value")));
 			}
 			
diff --git a/ICSharpCode.NRefactory.CSharp/Refactoring/CodeActions/RemoveBackingStoreAction.cs b/ICSharpCode.NRefactory.CSharp/Refactoring/CodeActions/RemoveBackingStoreAction.cs
index 6267e0c558..4e1add9b5f 100644
--- a/ICSharpCode.NRefactory.CSharp/Refactoring/CodeActions/RemoveBackingStoreAction.cs
+++ b/ICSharpCode.NRefactory.CSharp/Refactoring/CodeActions/RemoveBackingStoreAction.cs
@@ -89,7 +89,7 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 			var setterField = ScanSetter (context, propertyDeclaration);
 			if (setterField == null)
 				return null;
-			if (getterField.Region != setterField.Region)
+			if (!getterField.Equals(setterField))
 				return null;
 			return getterField;
 		}
diff --git a/ICSharpCode.NRefactory.CSharp/Refactoring/CodeIssues/ConstantConditionIssue.cs b/ICSharpCode.NRefactory.CSharp/Refactoring/CodeIssues/ConstantConditionIssue.cs
index f3d639be49..aac9409f8b 100644
--- a/ICSharpCode.NRefactory.CSharp/Refactoring/CodeIssues/ConstantConditionIssue.cs
+++ b/ICSharpCode.NRefactory.CSharp/Refactoring/CodeIssues/ConstantConditionIssue.cs
@@ -95,7 +95,7 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 				var value = (bool)resolveResult.ConstantValue;
 				var conditionalExpr = condition.Parent as ConditionalExpression;
 				var ifElseStatement = condition.Parent as IfElseStatement;
-				var valueStr = value.ToString ().ToLower ();
+				var valueStr = value.ToString ().ToLowerInvariant ();
 
 				CodeAction action;
 				if (conditionalExpr != null) {
diff --git a/ICSharpCode.NRefactory.Tests/CSharp/CodeActions/AddAnotherAccessorTests.cs b/ICSharpCode.NRefactory.Tests/CSharp/CodeActions/AddAnotherAccessorTests.cs
index 5f0369cbce..5e0bd1ae9d 100644
--- a/ICSharpCode.NRefactory.Tests/CSharp/CodeActions/AddAnotherAccessorTests.cs
+++ b/ICSharpCode.NRefactory.Tests/CSharp/CodeActions/AddAnotherAccessorTests.cs
@@ -64,6 +64,37 @@ namespace ICSharpCode.NRefactory.CSharp.CodeActions
 				"}", result);
 		}
 		
+		[Test]
+		public void TestAddSet_ReadOnlyField ()
+		{
+			string result = RunContextAction (
+				new AddAnotherAccessorAction (),
+				"class TestClass" + Environment.NewLine +
+				"{" + Environment.NewLine +
+				"	readonly int field;" + Environment.NewLine +
+				"	public int $Field {" + Environment.NewLine +
+				"		get {" + Environment.NewLine +
+				"			return field;" + Environment.NewLine +
+				"		}" + Environment.NewLine +
+				"	}" + Environment.NewLine +
+				"}"
+			);
+			
+			Assert.AreEqual (
+				"class TestClass" + Environment.NewLine +
+				"{" + Environment.NewLine +
+				"	readonly int field;" + Environment.NewLine +
+				"	public int Field {" + Environment.NewLine +
+				"		get {" + Environment.NewLine +
+				"			return field;" + Environment.NewLine +
+				"		}" + Environment.NewLine +
+				"		set {" + Environment.NewLine +
+				"			throw new System.NotImplementedException ();" + Environment.NewLine +
+				"		}" + Environment.NewLine +
+				"	}" + Environment.NewLine +
+				"}", result);
+		}
+		
 		[Test]
 		public void TestAddGet ()
 		{