A bit of refactoring to be able to find some issue...

GreenshotPlugin/UnmanagedHelpers/Enums/SendMessageTimeoutFlags.cs

@@ -0,0 +1,17 @@
+using System;
+using System.Diagnostics.CodeAnalysis;
+
+namespace GreenshotPlugin.UnmanagedHelpers.Enums
+{
+    /// <summary>
+    /// See: http://www.pinvoke.net/default.aspx/Enums/SendMessageTimeoutFlags.html
+    /// </summary>
+    [Flags]
+    [SuppressMessage("ReSharper", "InconsistentNaming")]
+    public enum SendMessageTimeoutFlags : uint {
+        SMTO_NORMAL				= 0x0,
+        SMTO_BLOCK				= 0x1,
+        SMTO_ABORTIFHUNG		= 0x2,
+        SMTO_NOTIMEOUTIFNOTHUNG	= 0x8
+    }
+}