Index: trunk/src/org/openstreetmap/josm/data/ImageData.java
===================================================================
--- trunk/src/org/openstreetmap/josm/data/ImageData.java	(revision 18420)
+++ trunk/src/org/openstreetmap/josm/data/ImageData.java	(revision 18421)
@@ -380,4 +380,6 @@
         if (fireUpdateEvent) {
             notifyImageUpdate();
+            // Fix JOSM #21521 -- when an image is removed, we need to update the selected image
+            this.updateSelectedImage();
         }
     }
Index: trunk/src/org/openstreetmap/josm/gui/layer/geoimage/ImageEntry.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/layer/geoimage/ImageEntry.java	(revision 18420)
+++ trunk/src/org/openstreetmap/josm/gui/layer/geoimage/ImageEntry.java	(revision 18421)
@@ -172,5 +172,5 @@
     @Override
     public boolean remove() {
-        this.dataSet.removeImage(this, false);
+        this.dataSet.removeImage(this, true);
         return true;
     }