Index: nhibernate/src/NHibernate.Test/ProxyInterface/CastleProxy.cs
===================================================================
--- nhibernate/src/NHibernate.Test/ProxyInterface/CastleProxy.cs	(revision 3262)
+++ nhibernate/src/NHibernate.Test/ProxyInterface/CastleProxy.cs	(working copy)
@@ -10,5 +10,7 @@
 		int Id { get; set; }
 
 		string Name { get; set; }
+
+		void ThrowDeepException();
 	}
 }
\ No newline at end of file
Index: nhibernate/src/NHibernate.Test/ProxyInterface/CastleProxyFixture.cs
===================================================================
--- nhibernate/src/NHibernate.Test/ProxyInterface/CastleProxyFixture.cs	(revision 3262)
+++ nhibernate/src/NHibernate.Test/ProxyInterface/CastleProxyFixture.cs	(working copy)
@@ -1,3 +1,4 @@
+using System;
 using System.Collections;
 using System.IO;
 using System.Runtime.Serialization;
@@ -110,5 +111,39 @@
 			Assert.IsNotNull(s.Load(typeof(CastleProxyImpl), 5), "should be proxy - even though it doesn't exists in db");
 			s.Close();
 		}
+
+		[Test]
+		public void ExceptionStackTrace()
+		{
+			ISession s = OpenSession();
+			CastleProxy ap = new CastleProxyImpl();
+			ap.Id = 1;
+			ap.Name = "first proxy";
+			s.Save(ap);
+			s.Flush();
+			s.Close();
+
+			s = OpenSession();
+			ap = (CastleProxy) s.Load(typeof(CastleProxyImpl), ap.Id);
+			Assert.IsFalse(NHibernateUtil.IsInitialized(ap), "check we have a proxy");
+
+			try
+			{
+				ap.ThrowDeepException();
+				Assert.Fail("Exception not thrown");
+			}
+			catch (ArgumentException ae)
+			{
+				Assert.AreEqual("thrown from Level2", ae.Message);
+
+				string[] stackTraceLines = ae.StackTrace.Split('\n');
+				Assert.IsTrue(stackTraceLines[0].Contains("Level2"), "top of exception stack is Level2()");
+				Assert.IsTrue(stackTraceLines[1].Contains("Level1"), "next on exception stack is Level1()");
+			}
+
+			s.Delete(ap);
+			s.Flush();
+			s.Close();
+		}
 	}
 }
\ No newline at end of file
Index: nhibernate/src/NHibernate.Test/ProxyInterface/CastleProxyImpl.cs
===================================================================
--- nhibernate/src/NHibernate.Test/ProxyInterface/CastleProxyImpl.cs	(revision 3262)
+++ nhibernate/src/NHibernate.Test/ProxyInterface/CastleProxyImpl.cs	(working copy)
@@ -11,6 +11,9 @@
 		private int _id;
 		private string _name;
 
+		private void Level1() { Level2(); }
+		private void Level2() { throw new ArgumentException("thrown from Level2"); }
+
 		#region CastleProxy Members
 
 		public int Id
@@ -25,6 +28,11 @@
 			set { _name = value; }
 		}
 
+		public void ThrowDeepException()
+		{
+			Level1();
+		}
+
 		#endregion
 	}
 }
\ No newline at end of file
Index: nhibernate/src/NHibernate/Proxy/Poco/Castle/CastleLazyInitializer.cs
===================================================================
--- nhibernate/src/NHibernate/Proxy/Poco/Castle/CastleLazyInitializer.cs	(revision 3262)
+++ nhibernate/src/NHibernate/Proxy/Poco/Castle/CastleLazyInitializer.cs	(working copy)
@@ -73,7 +73,18 @@
 			catch (TargetInvocationException tie)
 			{
 				// Propagate the inner exception so that the proxy throws the same exception as
-				// the real object would (though of course the stack trace will be probably lost).
+				// the real object would.
+
+				// Use private member _remoteStackTraceString to make the framework keep
+				// the original stack trace.
+				// Based on blog http://dotnetjunkies.com/WebLog/chris.taylor/archive/2004/03/03/8353.aspx
+				FieldInfo remoteStackTraceString =
+					typeof(Exception).GetField(	"_remoteStackTraceString",
+												BindingFlags.Instance | BindingFlags.NonPublic);
+
+				remoteStackTraceString.SetValue(tie.InnerException,
+												tie.InnerException.StackTrace + Environment.NewLine);
+
 				throw tie.InnerException;
 			}
 		}