add comments about .net 4.0 crash

README.md

@@ -20,6 +20,9 @@ For Windows 7 and older, please download Shadowsocks-win-x.x.x.zip.
 
 For Windows 8.1 and newer, please download Shadowsocks-win-dotnet4.0-x.x.x.zip.
 
+Notice there's a bug on .Net 4.0 version. If you encounter crashes, try using
+.Net 2.0 version. Please help us resolve this issue if you have any clue.
+
 ### Usage
 
 1. Find Shadowsocks icon in notification tray

shadowsocks-csharp/Controller/Local.cs

@@ -314,7 +314,7 @@ namespace Shadowsocks.Controller
                 }
                 else
                 {
-                    Console.WriteLine("bytesRead: " + bytesRead.ToString());
+                    //Console.WriteLine("bytesRead: " + bytesRead.ToString());
                     this.Close();
                 }
             }