Index: /trunk/src/org/openstreetmap/josm/gui/layer/markerlayer/MarkerLayer.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/layer/markerlayer/MarkerLayer.java	(revision 550)
+++ /trunk/src/org/openstreetmap/josm/gui/layer/markerlayer/MarkerLayer.java	(revision 551)
@@ -346,4 +346,6 @@
 							nextTime = true;
 						} else {
+							if (previousMarker == null)
+								previousMarker = startMarker; // if no previous one, play the first one again
 							((AudioMarker)previousMarker).play();
 							break;
@@ -356,4 +358,9 @@
 						previousMarker = marker;
 				}
+				if (nextTime) {
+					// there was no next marker in that layer, so play the last one again
+					((AudioMarker)startMarker).play();
+					return;
+				}
 			}
 		}