diff --git a/Implab/Diagnostics/Trace.cs b/Implab/Diagnostics/Trace.cs
--- a/Implab/Diagnostics/Trace.cs
+++ b/Implab/Diagnostics/Trace.cs
@@ -29,6 +29,7 @@ namespace Implab.Diagnostics {
         /// <param name="name">Name.</param>
         [Conditional("TRACE")]
         public static void StartLogicalOperation(string name) {
+            Channel.LogEvent(new TraceEvent(TraceContext.Instance.CurrentOperation, TraceEventType.OperationStarted, name));
             TraceContext.Instance.StartLogicalOperation(name);
         }
 
@@ -38,7 +39,7 @@ namespace Implab.Diagnostics {
         [Conditional("TRACE")]
         public static void EndLogicalOperation() {
             var op = TraceContext.Instance.EndLogicalOperation();
-            LogChannel<TraceEvent>.Default.LogEvent(new TraceEvent(op, TraceEventType.OperationCompleted, String.Format("-{0} : {1}ms", op.Name, op.Duration)));
+            Channel.LogEvent(new TraceEvent(op, TraceEventType.OperationCompleted, String.Format("-{0} : {1}ms", op.Name, op.Duration)));
         }
 
         /// <summary>
diff --git a/Implab/Diagnostics/TraceContext.cs b/Implab/Diagnostics/TraceContext.cs
--- a/Implab/Diagnostics/TraceContext.cs
+++ b/Implab/Diagnostics/TraceContext.cs
@@ -48,7 +48,7 @@ namespace Implab.Diagnostics {
         }
 
         public void StartLogicalOperation(string name) {
-            LogChannel<TraceEvent>.Default.LogEvent(new TraceEvent(TraceContext.Instance.CurrentOperation, TraceEventType.OperationStarted, name));
+            //LogChannel<TraceEvent>.Default.LogEvent(new TraceEvent(TraceContext.Instance.CurrentOperation, TraceEventType.OperationStarted, name));
             m_current.BeginLogicalOperation(name);
         }