diff --git a/src/AddIns/Debugger/Debugger.AddIn/Visualizers/Utils/DebuggerHelpers.cs b/src/AddIns/Debugger/Debugger.AddIn/Visualizers/Utils/DebuggerHelpers.cs
index 31114e777c..10cbf2d79f 100644
--- a/src/AddIns/Debugger/Debugger.AddIn/Visualizers/Utils/DebuggerHelpers.cs
+++ b/src/AddIns/Debugger/Debugger.AddIn/Visualizers/Utils/DebuggerHelpers.cs
@@ -39,6 +39,7 @@ namespace Debugger.AddIn.Visualizers.Utils
 		/// </summary>
 		public static ulong GetObjectAddress(this Value val)
 		{
+			if (val.IsNull) return 0;
 			ICorDebugReferenceValue refVal = val.CorReferenceValue;
 			return refVal.GetValue();
 		}
diff --git a/src/AddIns/Debugger/Debugger.Core/Value.cs b/src/AddIns/Debugger/Debugger.Core/Value.cs
index 23b56c108d..0e45de64b6 100644
--- a/src/AddIns/Debugger/Debugger.Core/Value.cs
+++ b/src/AddIns/Debugger/Debugger.Core/Value.cs
@@ -30,6 +30,9 @@ namespace Debugger
 		PauseSession   corValue_pauseSession;
 		DebugType      type;
 		
+		// Permanently stored as convinience so that it survives Continue
+		bool           isNull;
+		
 		/// <summary> The appdomain that owns the value </summary>
 		public AppDomain AppDomain {
 			get { return appDomain; }
@@ -51,8 +54,11 @@ namespace Debugger
 		[Debugger.Tests.Ignore]
 		public ICorDebugReferenceValue CorReferenceValue {
 			get {
+				if (IsNull) throw new GetValueException("Value is null");
+				
 				if (!(this.CorValue is ICorDebugReferenceValue))
 					throw new DebuggerException("Reference value expected");
+				
 				return (ICorDebugReferenceValue)this.CorValue;
 			}
 		}
@@ -78,6 +84,7 @@ namespace Debugger
 		public ICorDebugArrayValue CorArrayValue {
 			get {
 				if (IsNull) throw new GetValueException("Value is null");
+				
 				if (!this.Type.IsArray) throw new DebuggerException("Value is not an array");
 				
 				return (ICorDebugArrayValue)this.CorReferenceValue.Dereference();
@@ -125,10 +132,7 @@ namespace Debugger
 		
 		/// <summary> Returns true if the value is null </summary>
 		public bool IsNull {
-			get {
-				return this.CorValue is ICorDebugReferenceValue &&
-					   ((ICorDebugReferenceValue)this.CorValue).IsNull() != 0;
-			}
+			get { return isNull; }
 		}
 		
 		/// <summary>
@@ -166,6 +170,8 @@ namespace Debugger
 			this.corValue = corValue;
 			this.corValue_pauseSession = this.Process.PauseSession;
 			
+			this.isNull = corValue is ICorDebugReferenceValue && ((ICorDebugReferenceValue)corValue).IsNull() != 0;
+			
 			if (corValue is ICorDebugReferenceValue &&
 			    ((ICorDebugReferenceValue)corValue).GetValue() == 0 &&
 			    ((ICorDebugValue2)corValue).GetExactType() == null)
@@ -200,8 +206,8 @@ namespace Debugger
 			if (this.CorValue is ICorDebugHandleValue) {
 				return this;
 			} else if (this.CorValue is ICorDebugReferenceValue) {
-				if (this.CorReferenceValue.IsNull() > 0)
-					return this; // ("null" expression) TODO: It isn't permanent
+				if (this.IsNull)
+					return this; // ("null" expression) It isn't permanent
 				ICorDebugValue deRef = this.CorReferenceValue.Dereference();
 				if (deRef is ICorDebugHeapValue2) {
 					return new Value(appDomain, ((ICorDebugHeapValue2)deRef).CreateHandle(CorDebugHandleType.HANDLE_STRONG));
@@ -236,7 +242,7 @@ namespace Debugger
 			if (this.CorValue is ICorDebugReferenceValue) {
 				if (!(newCorValue is ICorDebugReferenceValue))
 					newCorValue = newValue.Box().CorValue;
-				this.CorReferenceValue.SetValue(((ICorDebugReferenceValue)newCorValue).GetValue());
+				((ICorDebugReferenceValue)this.CorValue).SetValue(((ICorDebugReferenceValue)newCorValue).GetValue());
 			} else {
 				this.CorGenericValue.SetRawValue(newValue.CorGenericValue.GetRawValue());
 			}
diff --git a/src/AddIns/Debugger/Debugger.Tests/Tests/StackFrame_VariablesLifetime.cs b/src/AddIns/Debugger/Debugger.Tests/Tests/StackFrame_VariablesLifetime.cs
index 150566a732..f46e5b7a10 100644
--- a/src/AddIns/Debugger/Debugger.Tests/Tests/StackFrame_VariablesLifetime.cs
+++ b/src/AddIns/Debugger/Debugger.Tests/Tests/StackFrame_VariablesLifetime.cs
@@ -122,7 +122,6 @@ namespace Debugger.Tests {
       <Value
         AsString="{Exception: Value is no longer valid}"
         IsInvalid="True"
-        IsNull="{Exception: Value is no longer valid}"
         IsReference="{Exception: Value is no longer valid}"
         PrimitiveValue="{Exception: Value is no longer valid}"
         Type="System.Int32" />
@@ -131,7 +130,6 @@ namespace Debugger.Tests {
       <Value
         AsString="{Exception: Value is no longer valid}"
         IsInvalid="True"
-        IsNull="{Exception: Value is no longer valid}"
         IsReference="{Exception: Value is no longer valid}"
         PrimitiveValue="{Exception: Value is no longer valid}"
         Type="System.Int32" />
@@ -140,7 +138,6 @@ namespace Debugger.Tests {
       <Value
         AsString="{Exception: Value is no longer valid}"
         IsInvalid="True"
-        IsNull="{Exception: Value is no longer valid}"
         IsReference="{Exception: Value is no longer valid}"
         PrimitiveValue="{Exception: Value is no longer valid}"
         Type="System.Int32" />
@@ -156,7 +153,6 @@ namespace Debugger.Tests {
       <Value
         AsString="{Exception: Value is no longer valid}"
         IsInvalid="True"
-        IsNull="{Exception: Value is no longer valid}"
         IsReference="{Exception: Value is no longer valid}"
         PrimitiveValue="{Exception: Value is no longer valid}"
         Type="System.Int32" />
@@ -165,7 +161,6 @@ namespace Debugger.Tests {
       <Value
         AsString="{Exception: Value is no longer valid}"
         IsInvalid="True"
-        IsNull="{Exception: Value is no longer valid}"
         IsReference="{Exception: Value is no longer valid}"
         PrimitiveValue="{Exception: Value is no longer valid}"
         Type="System.Int32" />
@@ -174,7 +169,6 @@ namespace Debugger.Tests {
       <Value
         AsString="{Exception: Value is no longer valid}"
         IsInvalid="True"
-        IsNull="{Exception: Value is no longer valid}"
         IsReference="{Exception: Value is no longer valid}"
         PrimitiveValue="{Exception: Value is no longer valid}"
         Type="System.Int32" />
@@ -183,7 +177,6 @@ namespace Debugger.Tests {
       <Value
         AsString="{Exception: Value is no longer valid}"
         IsInvalid="True"
-        IsNull="{Exception: Value is no longer valid}"
         IsReference="{Exception: Value is no longer valid}"
         PrimitiveValue="{Exception: Value is no longer valid}"
         Type="System.Int32" />
@@ -193,7 +186,6 @@ namespace Debugger.Tests {
       <Value
         AsString="{Exception: Value is no longer valid}"
         IsInvalid="True"
-        IsNull="{Exception: Value is no longer valid}"
         IsReference="{Exception: Value is no longer valid}"
         PrimitiveValue="{Exception: Value is no longer valid}"
         Type="System.Int32" />
@@ -202,7 +194,6 @@ namespace Debugger.Tests {
       <Value
         AsString="{Exception: Value is no longer valid}"
         IsInvalid="True"
-        IsNull="{Exception: Value is no longer valid}"
         IsReference="{Exception: Value is no longer valid}"
         PrimitiveValue="{Exception: Value is no longer valid}"
         Type="System.Int32" />
@@ -211,7 +202,6 @@ namespace Debugger.Tests {
       <Value
         AsString="{Exception: Value is no longer valid}"
         IsInvalid="True"
-        IsNull="{Exception: Value is no longer valid}"
         IsReference="{Exception: Value is no longer valid}"
         PrimitiveValue="{Exception: Value is no longer valid}"
         Type="System.Int32" />
@@ -220,7 +210,6 @@ namespace Debugger.Tests {
       <Value
         AsString="{Exception: Value is no longer valid}"
         IsInvalid="True"
-        IsNull="{Exception: Value is no longer valid}"
         IsReference="{Exception: Value is no longer valid}"
         PrimitiveValue="{Exception: Value is no longer valid}"
         Type="System.Int32" />
@@ -236,7 +225,6 @@ namespace Debugger.Tests {
       <Value
         AsString="{Exception: Value is no longer valid}"
         IsInvalid="True"
-        IsNull="{Exception: Value is no longer valid}"
         IsReference="{Exception: Value is no longer valid}"
         PrimitiveValue="{Exception: Value is no longer valid}"
         Type="System.Int32" />
@@ -245,7 +233,6 @@ namespace Debugger.Tests {
       <Value
         AsString="{Exception: Value is no longer valid}"
         IsInvalid="True"
-        IsNull="{Exception: Value is no longer valid}"
         IsReference="{Exception: Value is no longer valid}"
         PrimitiveValue="{Exception: Value is no longer valid}"
         Type="System.Int32" />
@@ -254,7 +241,6 @@ namespace Debugger.Tests {
       <Value
         AsString="{Exception: Value is no longer valid}"
         IsInvalid="True"
-        IsNull="{Exception: Value is no longer valid}"
         IsReference="{Exception: Value is no longer valid}"
         PrimitiveValue="{Exception: Value is no longer valid}"
         Type="System.Int32" />
@@ -263,7 +249,6 @@ namespace Debugger.Tests {
       <Value
         AsString="{Exception: Value is no longer valid}"
         IsInvalid="True"
-        IsNull="{Exception: Value is no longer valid}"
         IsReference="{Exception: Value is no longer valid}"
         PrimitiveValue="{Exception: Value is no longer valid}"
         Type="System.Int32" />