Index: linux/glwindow.cpp
===================================================================
--- linux/glwindow.cpp	(revision 1278)
+++ linux/glwindow.cpp	(working copy)
@@ -58,6 +58,9 @@
     if (event->button == 1)
       wnd->OnLeftButtonDown (x, y, (event->state & GDK_CONTROL_MASK) != 0,
                              (event->state & GDK_SHIFT_MASK) != 0);
+    else if (event->button == 2)
+      wnd->OnMiddleButtonDown (x, y, (event->state & GDK_CONTROL_MASK) != 0,
+                               (event->state & GDK_SHIFT_MASK) != 0);
     else if (event->button == 3)
       wnd->OnRightButtonDown (x, y, (event->state & GDK_CONTROL_MASK) != 0,
                               (event->state & GDK_SHIFT_MASK) != 0);
@@ -89,6 +92,9 @@
   if (event->button == 1)
     wnd->OnLeftButtonUp (x, y, (event->state & GDK_CONTROL_MASK) != 0,
                          (event->state & GDK_SHIFT_MASK) != 0);
+  else if (event->button == 2)
+    wnd->OnMiddleButtonUp (x, y, (event->state & GDK_CONTROL_MASK) != 0,
+                           (event->state & GDK_SHIFT_MASK) != 0);
   else if (event->button == 3)
     wnd->OnRightButtonUp (x, y, (event->state & GDK_CONTROL_MASK) != 0,
                           (event->state & GDK_SHIFT_MASK) != 0);