Index: Core/GIS/src/Core.GIS.SharpMap/Rendering/Thematics/CustomTheme.cs
===================================================================
diff -u -r29074485032e73e932140ea9980c21d929e4dc08 -ra60bbf1de4ed3d809e8325c0b7359f7786f4a16d
--- Core/GIS/src/Core.GIS.SharpMap/Rendering/Thematics/CustomTheme.cs	(.../CustomTheme.cs)	(revision 29074485032e73e932140ea9980c21d929e4dc08)
+++ Core/GIS/src/Core.GIS.SharpMap/Rendering/Thematics/CustomTheme.cs	(.../CustomTheme.cs)	(revision a60bbf1de4ed3d809e8325c0b7359f7786f4a16d)
@@ -94,7 +94,21 @@
             set
             {
                 OnPropertyChanging("DefaultStyle");
+
+                if (defaultStyle != null)
+                {
+                    defaultStyle.PropertyChanging -= OnPropertyChanging;
+                    defaultStyle.PropertyChanged -= OnPropertyChanged;
+                }
+
                 defaultStyle = value;
+
+                if (defaultStyle != null)
+                {
+                    defaultStyle.PropertyChanging += OnPropertyChanging;
+                    defaultStyle.PropertyChanged += OnPropertyChanged;
+                }
+
                 OnPropertyChanged("DefaultStyle");
             }
         }
@@ -223,24 +237,40 @@
 
         public event PropertyChangingEventHandler PropertyChanging;
 
-        protected void OnPropertyChanging(string propertyName)
+        private void OnPropertyChanging(string propertyName)
         {
             if (PropertyChanging != null)
             {
                 PropertyChanging(this, new PropertyChangingEventArgs(propertyName));
             }
         }
 
+        private void OnPropertyChanging(object sender, PropertyChangingEventArgs e)
+        {
+            if (PropertyChanging != null)
+            {
+                PropertyChanging(sender, e);
+            }
+        }
+
         public event PropertyChangedEventHandler PropertyChanged;
 
-        protected void OnPropertyChanged(string propertyName)
+        private void OnPropertyChanged(string propertyName)
         {
             if (PropertyChanged != null)
             {
                 PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
             }
         }
 
+        private void OnPropertyChanged(object sender, PropertyChangedEventArgs e)
+        {
+            if (PropertyChanged != null)
+            {
+                PropertyChanged(sender, e);
+            }
+        }
+
         #endregion
     }
 }
\ No newline at end of file
Index: Core/GIS/test/Core.GIS.SharpMap.Tests/Core.GIS.SharpMap.Tests.csproj
===================================================================
diff -u -rb6ffe77a74979f9893a1b338a13acce47c57feda -ra60bbf1de4ed3d809e8325c0b7359f7786f4a16d
--- Core/GIS/test/Core.GIS.SharpMap.Tests/Core.GIS.SharpMap.Tests.csproj	(.../Core.GIS.SharpMap.Tests.csproj)	(revision b6ffe77a74979f9893a1b338a13acce47c57feda)
+++ Core/GIS/test/Core.GIS.SharpMap.Tests/Core.GIS.SharpMap.Tests.csproj	(.../Core.GIS.SharpMap.Tests.csproj)	(revision a60bbf1de4ed3d809e8325c0b7359f7786f4a16d)
@@ -137,6 +137,7 @@
     <Compile Include="Rendering\Thematics\CategorialThemeItemTest.cs" />
     <Compile Include="Rendering\Thematics\CategorialThemeTest.cs" />
     <Compile Include="Rendering\Thematics\ColorBlendTest.cs" />
+    <Compile Include="Rendering\Thematics\CustomThemeTest.cs" />
     <Compile Include="Rendering\Thematics\GradientThemeItemTest.cs" />
     <Compile Include="Rendering\Thematics\GradientThemeTest.cs" />
     <Compile Include="Rendering\VectorRenderingHelperTest.cs" />
Index: Core/GIS/test/Core.GIS.SharpMap.Tests/Rendering/Thematics/CategorialThemeTest.cs
===================================================================
diff -u -r0c6e0021eebf932c06c7f6905dd3abad31ba60d6 -ra60bbf1de4ed3d809e8325c0b7359f7786f4a16d
--- Core/GIS/test/Core.GIS.SharpMap.Tests/Rendering/Thematics/CategorialThemeTest.cs	(.../CategorialThemeTest.cs)	(revision 0c6e0021eebf932c06c7f6905dd3abad31ba60d6)
+++ Core/GIS/test/Core.GIS.SharpMap.Tests/Rendering/Thematics/CategorialThemeTest.cs	(.../CategorialThemeTest.cs)	(revision a60bbf1de4ed3d809e8325c0b7359f7786f4a16d)
@@ -180,13 +180,13 @@
         }
 
         [Test]
-        public void CategorialThemeItemBubblesPropertyChangesOfDefaultStyle()
+        public void CategorialThemeBubblesPropertyChangesOfDefaultStyle()
         {
             var counter = 0;
             var defaultStyle = new VectorStyle();
-            var categorialThemeItem = new CategorialTheme { DefaultStyle = defaultStyle };
+            var categorialTheme = new CategorialTheme { DefaultStyle = defaultStyle };
 
-            ((INotifyPropertyChanged) categorialThemeItem).PropertyChanged += (sender, e) =>
+            ((INotifyPropertyChanged) categorialTheme).PropertyChanged += (sender, e) =>
             {
                 if (sender is IStyle)
                 {
Index: Core/GIS/test/Core.GIS.SharpMap.Tests/Rendering/Thematics/CustomThemeTest.cs
===================================================================
diff -u
--- Core/GIS/test/Core.GIS.SharpMap.Tests/Rendering/Thematics/CustomThemeTest.cs	(revision 0)
+++ Core/GIS/test/Core.GIS.SharpMap.Tests/Rendering/Thematics/CustomThemeTest.cs	(revision a60bbf1de4ed3d809e8325c0b7359f7786f4a16d)
@@ -0,0 +1,32 @@
+using System.ComponentModel;
+using Core.GIS.SharpMap.Api;
+using Core.GIS.SharpMap.Rendering.Thematics;
+using Core.GIS.SharpMap.Styles;
+using NUnit.Framework;
+
+namespace Core.GIS.SharpMap.Tests.Rendering.Thematics
+{
+    [TestFixture]
+    public class CustomThemeTest
+    {
+        [Test]
+        public void CustomThemeBubblesPropertyChangesOfDefaultStyle()
+        {
+            var counter = 0;
+            var defaultStyle = new VectorStyle();
+            var customTheme = new CustomTheme(null) { DefaultStyle = defaultStyle };
+
+            ((INotifyPropertyChanged) customTheme).PropertyChanged += (sender, e) =>
+            {
+                if (sender is IStyle)
+                {
+                    counter++;
+                }
+            };
+
+            defaultStyle.EnableOutline = true;
+
+            Assert.AreEqual(1, counter);
+        }
+    }
+}