Index: trunk/src/org/openstreetmap/josm/gui/MapStatus.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/MapStatus.java	(revision 3628)
+++ trunk/src/org/openstreetmap/josm/gui/MapStatus.java	(revision 3629)
@@ -171,5 +171,12 @@
                     // access to the data need to be restarted, if the main thread modifies
                     // the data.
+                    DataSet ds = null;
                     try {
+                        ds = mv.getCurrentDataSet();
+                        if (ds != null) {
+                            // This is not perfect, if current dataset was changed during execution, the lock would be useless
+                            ds.getReadLock().lock();
+                        }
+
                         // Set the text label in the bottom status bar
                         statusBarElementUpdate(ms);
@@ -237,4 +244,8 @@
                     } catch (NullPointerException x) {
                         //x.printStackTrace();
+                    } finally {
+                        if (ds != null) {
+                            ds.getReadLock().unlock();
+                        }
                     }
                 }