diff --git a/BizHawk.Client.Common/movie/tasproj/TasMovie.History.cs b/BizHawk.Client.Common/movie/tasproj/TasMovie.History.cs
index 5a0c12abb2..2ddc1a639e 100644
--- a/BizHawk.Client.Common/movie/tasproj/TasMovie.History.cs
+++ b/BizHawk.Client.Common/movie/tasproj/TasMovie.History.cs
@@ -283,6 +283,11 @@ namespace BizHawk.Client.Common
 		{
 			if (IsRecording || force)
 			{
+				if (oldPosition == -1)
+					name = "Set Marker at frame " + newMarker.Frame;
+				else
+					name = "Remove Marker at frame " + oldPosition;
+
 				AddMovieAction(name);
 				History.Last().Add(new MovieActionMarker(newMarker, oldPosition, old_message));
 			}
diff --git a/BizHawk.Client.Common/movie/tasproj/TasMovieMarker.cs b/BizHawk.Client.Common/movie/tasproj/TasMovieMarker.cs
index 41fca12525..3328df7ed4 100644
--- a/BizHawk.Client.Common/movie/tasproj/TasMovieMarker.cs
+++ b/BizHawk.Client.Common/movie/tasproj/TasMovieMarker.cs
@@ -169,7 +169,7 @@ namespace BizHawk.Client.Common
 
 		public new void Remove(TasMovieMarker item)
 		{
-			if (item == null) // TODO: Don't do this.
+			if (item == null || item.Frame == 0) // TODO: Don't do this.
 				return;
 			_movie.ChangeLog.AddMarkerChange(null, item.Frame, item.Message);
 			base.Remove(item);
diff --git a/BizHawk.Client.Common/movie/tasproj/TasStateManager.cs b/BizHawk.Client.Common/movie/tasproj/TasStateManager.cs
index 566c5d866d..06a6e75f86 100644
--- a/BizHawk.Client.Common/movie/tasproj/TasStateManager.cs
+++ b/BizHawk.Client.Common/movie/tasproj/TasStateManager.cs
@@ -320,7 +320,7 @@ namespace BizHawk.Client.Common
 
 			for (int i = from; i < upTo; i++)
 			{
-				if (!_movie[i].Lagged.Value)
+				if (_movie[i].Lagged == null)
 					return false;
 			}
 
diff --git a/BizHawk.Client.EmuHawk/tools/TAStudio/MarkerControl.cs b/BizHawk.Client.EmuHawk/tools/TAStudio/MarkerControl.cs
index 500ee69340..0c6818d5a8 100644
--- a/BizHawk.Client.EmuHawk/tools/TAStudio/MarkerControl.cs
+++ b/BizHawk.Client.EmuHawk/tools/TAStudio/MarkerControl.cs
@@ -187,6 +187,7 @@ namespace BizHawk.Client.EmuHawk
 				Markers.Add(new TasMovieMarker(markerFrame, ""));
 				UpdateValues();
 			}
+			Tastudio.RefreshDialog();
 		}
 
 		public void EditMarkerPopUp(TasMovieMarker marker)
diff --git a/BizHawk.Client.EmuHawk/tools/TAStudio/UndoHistoryForm.cs b/BizHawk.Client.EmuHawk/tools/TAStudio/UndoHistoryForm.cs
index b15d391224..692f8ef1b8 100644
--- a/BizHawk.Client.EmuHawk/tools/TAStudio/UndoHistoryForm.cs
+++ b/BizHawk.Client.EmuHawk/tools/TAStudio/UndoHistoryForm.cs
@@ -44,9 +44,9 @@ namespace BizHawk.Client.EmuHawk
 				return;
 
 			if (row == log.UndoIndex)
-				color = Color.Green;
+				color = TAStudio.GreenZone_InputLog;
 			else if (row > log.UndoIndex)
-				color = Color.Red;
+				color = TAStudio.LagZone_InputLog;
 		}
 
 		private string _lastUndoAction = null;
@@ -55,7 +55,7 @@ namespace BizHawk.Client.EmuHawk
 			HistoryView.ItemCount = log.Names.Count;
 			if (AutoScrollCheck.Checked && _lastUndoAction != log.NextUndoStepName)
 			{
-				HistoryView.ensureVisible(log.UndoIndex - 1);
+				HistoryView.ensureVisible(log.UndoIndex);
 				HistoryView.clearSelection();
 				HistoryView.SelectItem(log.UndoIndex - 1, true);
 			}