Index: trunk/src/org/openstreetmap/josm/gui/tagging/presets/items/ComboMultiSelect.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/tagging/presets/items/ComboMultiSelect.java	(revision 17917)
+++ trunk/src/org/openstreetmap/josm/gui/tagging/presets/items/ComboMultiSelect.java	(revision 17919)
@@ -397,4 +397,12 @@
     public void addCommands(List<Tag> changedTags) {
         String value = getSelectedValue();
+
+        // no change if same as before
+        if (originalValue == null) {
+            if (value.isEmpty())
+                return;
+        } else if (value.equals(originalValue.toString()))
+            return;
+
         if (isUseLastAsDefault()) {
             LAST_VALUES.put(key, value);