Index: src/org/openstreetmap/josm/gui/SelectionManager.java
===================================================================
--- src/org/openstreetmap/josm/gui/SelectionManager.java	(revision 219)
+++ src/org/openstreetmap/josm/gui/SelectionManager.java	(working copy)
@@ -162,7 +162,7 @@
 	 * If the correct button, from the "drawing rectangle" mode
 	 */
 	public void mousePressed(MouseEvent e) {
-		if (e.getButton() == MouseEvent.BUTTON1)
+		if (e.getButton() == MouseEvent.BUTTON1 || e.getButton() == MouseEvent.BUTTON3)
 			mousePosStart = mousePos = e.getPoint();
 	}
 
@@ -194,7 +194,7 @@
 	 * Check the state of the keys and buttons and set the selection accordingly.
 	 */
 	public void mouseReleased(MouseEvent e) {
-		if (e.getButton() != MouseEvent.BUTTON1)
+		if (e.getButton() != MouseEvent.BUTTON1 && e.getButton() != MouseEvent.BUTTON3)
 			return;
 		if (mousePos == null || mousePosStart == null)
 			return; // injected release from outside
@@ -206,7 +206,7 @@
 		mousePos = null;
 
 		boolean shift = (e.getModifiersEx() & MouseEvent.SHIFT_DOWN_MASK) != 0;
-		boolean alt = (e.getModifiersEx() & MouseEvent.ALT_DOWN_MASK) != 0;
+		boolean alt = (e.getModifiersEx() & MouseEvent.ALT_DOWN_MASK) != 0 || e.getButton() == MouseEvent.BUTTON3;
 		boolean ctrl = (e.getModifiersEx() & MouseEvent.CTRL_DOWN_MASK) != 0;
 		if ((e.getModifiersEx() & MouseEvent.BUTTON3_DOWN_MASK) == 0)
 			selectionEndedListener.selectionEnded(r, alt, shift, ctrl);
