diff -Nru fgfs-base-2.11.0+201306072000~gitb3ad2aa/Nasal/canvas/gui.nas fgfs-base-2.11.0+201306080800~gita7e94ce/Nasal/canvas/gui.nas
--- fgfs-base-2.11.0+201306072000~gitb3ad2aa/Nasal/canvas/gui.nas	2013-06-07 01:05:22.000000000 +0000
+++ fgfs-base-2.11.0+201306080800~gita7e94ce/Nasal/canvas/gui.nas	2013-06-08 13:05:45.000000000 +0000
@@ -27,8 +27,13 @@
   del: func
   {
     me._node.remove();
+    me._node = nil;
+
     if( me["_canvas"] != nil )
+    {
       me._canvas.del();
+      me._canvas = nil;
+    }
   },
   # Create the canvas to be used for this Window
   #
@@ -147,6 +152,7 @@
     me.set("decoration-border", "25 1 1");
     me.set("shadow-inset", int((1 - math.cos(45 * D2R)) * border_radius + 0.5));
     me.set("shadow-radius", 5);
+    me.setBool("update", 1);
 
     var canvas_deco = me.getCanvasDecoration();
     canvas_deco.addEventListener("mousedown", func me.raise());
diff -Nru fgfs-base-2.11.0+201306072000~gitb3ad2aa/Shaders/urban.frag fgfs-base-2.11.0+201306080800~gita7e94ce/Shaders/urban.frag
--- fgfs-base-2.11.0+201306072000~gitb3ad2aa/Shaders/urban.frag	2013-04-28 13:35:47.000000000 +0000
+++ fgfs-base-2.11.0+201306080800~gita7e94ce/Shaders/urban.frag	2013-06-08 13:05:45.000000000 +0000
@@ -89,9 +89,9 @@
                 //use additional convergence speed-up
                 #ifdef USE_QDM_ASCEND_INTERVAL
                 if(frac(level*0.5) > EPSILON)
-                  level++;
-                #elseif USE_QDM_ASCEND_CONST
-                 level++;
+                    level++;
+                #elif USE_QDM_ASCEND_CONST
+                level++;
                 #endif
             }
             p2 = p + v * d;
diff -Nru fgfs-base-2.11.0+201306072000~gitb3ad2aa/debian/changelog fgfs-base-2.11.0+201306080800~gita7e94ce/debian/changelog
--- fgfs-base-2.11.0+201306072000~gitb3ad2aa/debian/changelog	2013-06-08 01:05:18.000000000 +0000
+++ fgfs-base-2.11.0+201306080800~gita7e94ce/debian/changelog	2013-06-08 13:05:53.000000000 +0000
@@ -1,3 +1,15 @@
+fgfs-base (2.11.0+201306080800~gita7e94ce-0ubuntu0ppa1) raring; urgency=low
+
+  [ Gijs de Rooy ]
+  * Fix urban shader compile error. #elseif is an incorrect directive, #elif is the correct one. Thanks to colintoal for reporting.
+
+  [ Thomas Geymayer ]
+  * Canvas window: allow gc to release resources
+
+  [ Saikrishna Arcot ]
+
+ -- Saikrishna Arcot <saiarcot895@gmail.com>  Sat, 08 Jun 2013 08:05:53 -0500
+
 fgfs-base (2.11.0+201306072000~gitb3ad2aa-0ubuntu0ppa1) raring; urgency=low
 
   [ Csaba Halasz ]