diff --git a/tsmark/video_annotator.py b/tsmark/video_annotator.py
index c83d09d..7304bae 100755
--- a/tsmark/video_annotator.py
+++ b/tsmark/video_annotator.py
@@ -842,6 +842,7 @@ class World:
         if point_index is None:
             point_index = self.point_index
         if not point_index in self.points:
+            self.points_interpolation_required[point_index] = []
             return
         try:
 
@@ -865,6 +866,10 @@ class World:
 
             new_points = {k: v for k, v in self.points_interpolated[point_index].items()}
 
+            if len(self.points[point_index]) == 0:  # no points yet
+                self.points_interpolation_required[point_index] = []
+                return
+
             if len(self.points[point_index]) == 1:  # only one point added
                 key = list(self.points[point_index].keys())[0]
                 vals = self.points[point_index][key]
@@ -1550,7 +1555,7 @@ class World:
                             self.point_click = 0
                         else:
                             self.point_index = chr(k2)
-                            self.interpolate_set(refresh=True)
+                            self.interpolate_set(point_index=self.point_index, refresh=True)
                 elif k & 0xFF == ord("g"):  # Go to
                     self.shadow_text(
                         frame_visu,