diff --git a/.gitignore b/.gitignore
index bff0826..1afe0de 100644
--- a/.gitignore
+++ b/.gitignore
@@ -110,8 +110,8 @@
 /lib/c_glib/test/testtransportsocket
 /lib/c_glib/thriftc.pc
 /lib/c_glib/thrift_c_glib.pc
-/lib/csharp/src/bin/
-/lib/csharp/src/obj/
+/lib/csharp/**/bin/
+/lib/csharp/**/obj/
 /lib/d/libthriftd.a
 /lib/d/test/serialization_benchmark
 /lib/d/test/transport_test
diff --git a/lib/csharp/src/Transport/THttpClient.cs b/lib/csharp/src/Transport/THttpClient.cs
index 78653f3..d19b7a7 100644
--- a/lib/csharp/src/Transport/THttpClient.cs
+++ b/lib/csharp/src/Transport/THttpClient.cs
@@ -216,7 +216,6 @@
             return connection;
 		}
 
-#if SILVERLIGHT
         public override IAsyncResult BeginFlush(AsyncCallback callback, object state)
         {
             // Extract request and reset buffer
@@ -267,7 +266,6 @@
 
         }
 
-
         private void GetRequestStreamCallback(IAsyncResult asynchronousResult)
         {
             var flushAsyncResult = (FlushAsyncResult)asynchronousResult.AsyncState;
@@ -375,7 +373,6 @@
             }
         }
 
-#endif
 #region " IDisposable Support "
 		private bool _IsDisposed;
 
diff --git a/lib/csharp/src/Transport/TTransport.cs b/lib/csharp/src/Transport/TTransport.cs
index c03e9c2..745aa78 100644
--- a/lib/csharp/src/Transport/TTransport.cs
+++ b/lib/csharp/src/Transport/TTransport.cs
@@ -76,11 +76,16 @@
         
         public virtual IAsyncResult BeginFlush(AsyncCallback callback, object state)
         {
-            return null;
+            throw new TTransportException(
+                TTransportException.ExceptionType.Unknown,
+                "Asynchronous operations are not supported by this transport.");
         }
 
         public virtual void EndFlush(IAsyncResult asyncResult)
         {
+            throw new TTransportException(
+                TTransportException.ExceptionType.Unknown,
+                "Asynchronous operations are not supported by this transport.");
         }
 
 		#region " IDisposable Support "