diff --git a/ChangeLog b/ChangeLog
index ad0b143..6b8471b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2005-11-30  Aaron Bockover  <aaron@aaronbock.net>
+
+	* src/HalDevice.cs: Use DBusError when adding/removing property watch
+	* src/HalTest.cs: Stripped down test
+	* src/Makefile.am: Added DBusError.cs
+	* src/DBusError.cs: Bindings to DBusError (dbus_error_init, 
+	dbus_error_free, dbus_error_is_set)
+	* src/HalContext.cs: Use DBusError in places
+
 2005-11-26  Aaron Bockover  <aaron@aaronbock.net>
 
 	* src/HalContext.cs: New Parent property that returns an instantiated
diff --git a/hal-sharp.mdp b/hal-sharp.mdp
index c0b059a..82bada3 100644
--- a/hal-sharp.mdp
+++ b/hal-sharp.mdp
@@ -25,6 +25,7 @@
     <File name="./src/HalContext.cs" subtype="Code" buildaction="Compile" />
     <File name="./src/HalDefines.cs" subtype="Code" buildaction="Compile" />
     <File name="./src/HalCallbacks.cs" subtype="Code" buildaction="Compile" />
+    <File name="./src/DBusError.cs" subtype="Code" buildaction="Compile" />
   </Contents>
   <References>
     <ProjectReference type="Gac" localcopy="True" refto="Mono.Posix, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=0738eb9f132ed756" />
diff --git a/src/DBusError.cs b/src/DBusError.cs
new file mode 100644
index 0000000..4433f9d
--- /dev/null
+++ b/src/DBusError.cs
@@ -0,0 +1,82 @@
+using System;
+using System.Runtime.InteropServices;
+using Mono.Unix;
+
+namespace Hal
+{
+    public class DBusError : IDisposable
+    {
+        [StructLayout(LayoutKind.Sequential)]
+        private struct UnmanagedError
+        {
+            public IntPtr name;
+            public IntPtr message;
+            public uint dummy1;
+            public uint dummy2;
+            public uint dummy3;
+            public uint dummy4;
+            public uint dummy5;
+            public IntPtr padding1;        
+        }
+        
+        [DllImport("libdbus-1")]
+        private static extern void dbus_error_init(IntPtr handle);
+        
+        [DllImport("libdbus-1")]
+        private static extern void dbus_error_free(IntPtr handle);
+        
+        [DllImport("libdbus-1")]
+        private static extern bool dbus_error_is_set(IntPtr handle);
+        
+        private IntPtr error_ptr;
+        private UnmanagedError error;
+
+        public DBusError()
+        {
+            error = new UnmanagedError();
+            error_ptr = Marshal.AllocHGlobal(Marshal.SizeOf(error));
+            dbus_error_init(error_ptr);
+        }
+        
+        public void Dispose()
+        {
+            dbus_error_free(error_ptr);
+            Marshal.FreeHGlobal(error_ptr);
+        }
+        
+        public void ThrowExceptionIfSet(string message)
+        {
+            if(IsSet) {
+                message += String.Format(": [{0}] {1}", Name, Message);
+                Dispose();
+                throw new HalException(message);
+            } else {
+                Dispose();
+            }
+        }
+        
+        public bool IsSet {
+            get {
+                return dbus_error_is_set(error_ptr);
+            }
+        }
+        
+        public string Name {
+            get {
+                return UnixMarshal.PtrToString(error.name);
+            }
+        }
+        
+        public string Message {
+            get {
+                return UnixMarshal.PtrToString(error.message);
+            }
+        }
+        
+        public IntPtr Raw {
+            get {
+                return error_ptr;
+            }
+        }
+    }
+}
diff --git a/src/HalContext.cs b/src/HalContext.cs
index 36dcc3b..156423f 100644
--- a/src/HalContext.cs
+++ b/src/HalContext.cs
@@ -101,10 +101,13 @@ namespace Hal
         
         public void Initialize()
         {
-            if(!Unmanaged.libhal_ctx_init(ctx_handle, IntPtr.Zero)) {
-                throw new HalException("Could not initialize HAL Context");
+            DBusError error = new DBusError();
+            if(!Unmanaged.libhal_ctx_init(ctx_handle, error.Raw)) {
+                error.ThrowExceptionIfSet("Could not initialize HAL Context");
+                return;
             }
             
+            error.Dispose();
             initialized = true;
         }
         
diff --git a/src/HalDevice.cs b/src/HalDevice.cs
index 1b0e541..fb7cd28 100644
--- a/src/HalDevice.cs
+++ b/src/HalDevice.cs
@@ -188,10 +188,14 @@ namespace Hal
         public bool WatchProperties
         {
             set {
-                bool result = value 
-                    ? Unmanaged.libhal_device_add_property_watch(ctx.Raw, udi, IntPtr.Zero) 
-                    : Unmanaged.libhal_device_remove_property_watch(ctx.Raw, udi, IntPtr.Zero);
+                DBusError error = new DBusError();
                 
+                bool result = value 
+                    ? Unmanaged.libhal_device_add_property_watch(ctx.Raw, udi, error.Raw) 
+                    : Unmanaged.libhal_device_remove_property_watch(ctx.Raw, udi, error.Raw);
+
+                error.ThrowExceptionIfSet("Could not update watch on property");
+
                 if(!result) {
                     throw new HalException("Could not " + (value ? "add" : "remove") + " property watch");
                 }
diff --git a/src/HalTest.cs b/src/HalTest.cs
index 5ae5e5b..2aa223f 100644
--- a/src/HalTest.cs
+++ b/src/HalTest.cs
@@ -29,14 +29,10 @@
 using System;
 using Hal;
 
-public class Entry
+public static class HalTest
 {
-    public static void Main()
+    public static void Main(string [] args)
     {
-        using(Context ctx = new Context()) {
-            foreach(Device device in Device.FindByCapability(ctx, "portable_audio_player")) {
-                device.Print();
-            } 
-        }
+        Context ctx = new Context();
     }
 }
diff --git a/src/Makefile.am b/src/Makefile.am
index c45d959..a4ec7fc 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -6,6 +6,7 @@ CLEANFILES = hal-sharp.dll hal-test.exe
 DISTCLEANFILES = Makefile.in *.mdb AssemblyInfo.cs hal-sharp.dll.config
 
 halsharp_sources = \
+	DBusError.cs \
 	HalContext.cs \
 	HalDevice.cs \
 	HalUnmanaged.cs \