Fixed bug that caused Error/Warning markers not to reappear after debugging.

src/Main/Base/Project/Src/Services/Debugger/DebuggerService.cs

@@ -89,6 +89,15 @@ namespace ICSharpCode.SharpDevelop.Debugging
 			}
 		}
 		
+		static bool debuggerStarted;
+		
+		/// <summary>
+		/// Gets whether the debugger is currently active.
+		/// </summary>
+		public static bool IsDebuggerStarted {
+			get { return debuggerStarted; }
+		}
+		
 		public static event EventHandler DebugStarting;
 		public static event EventHandler DebugStarted;
 		public static event EventHandler DebugStopped;
@@ -110,12 +119,14 @@ namespace ICSharpCode.SharpDevelop.Debugging
 		
 		static void OnDebugStarted(object sender, EventArgs e)
 		{
+			debuggerStarted = true;
 			if (DebugStarted != null)
 				DebugStarted(null, e);
 		}
 		
 		static void OnDebugStopped(object sender, EventArgs e)
 		{
+			debuggerStarted = false;
 			if (debugFeature != null)
 				debugFeature.EndTracking();
 			

src/Main/Base/Project/Src/Services/Tasks/ErrorPainter.cs

@@ -72,7 +72,7 @@ namespace ICSharpCode.SharpDevelop
 		void UpdateEnabled()
 		{
 			bool newEnabled = textEditor.Options.UnderlineErrors;
-			if (DebuggerService.IsDebuggerLoaded && DebuggerService.CurrentDebugger.IsDebugging)
+			if (DebuggerService.IsDebuggerStarted)
 				newEnabled = false;
 			
 			if (isEnabled != newEnabled) {