Index: applications/editors/josm/plugins/measurement/src/org/openstreetmap/josm/plugins/measurement/MeasurementDialog.java
===================================================================
--- applications/editors/josm/plugins/measurement/src/org/openstreetmap/josm/plugins/measurement/MeasurementDialog.java	(revision 28898)
+++ applications/editors/josm/plugins/measurement/src/org/openstreetmap/josm/plugins/measurement/MeasurementDialog.java	(revision 29344)
@@ -24,4 +24,5 @@
 import org.openstreetmap.josm.gui.dialogs.ToggleDialog;
 import org.openstreetmap.josm.gui.help.HelpUtil;
+import org.openstreetmap.josm.gui.util.GuiHelper;
 import org.openstreetmap.josm.tools.ImageProvider;
 import org.openstreetmap.josm.tools.Shortcut;
@@ -159,7 +160,17 @@
             }
         }
-        selectLengthLabel.setText(NavigatableComponent.getDistText(length));
-        segAngleLabel.setText(new DecimalFormat("#0.0").format(segAngle) + " \u00b0");
-        selectAreaLabel.setText(NavigatableComponent.getAreaText(area));
+        
+        final String lengthLabel = NavigatableComponent.getDistText(length);
+        final String angleLabel = new DecimalFormat("#0.0").format(segAngle) + " \u00b0";
+        final String areaLabel = NavigatableComponent.getAreaText(area);
+        
+        GuiHelper.runInEDT(new Runnable() {
+            @Override
+            public void run() {
+                selectLengthLabel.setText(lengthLabel);
+                segAngleLabel.setText(angleLabel);
+                selectAreaLabel.setText(areaLabel);
+            }
+        });
 	}