Index: compiz-0.7.4/src/window.c
===================================================================
--- compiz-0.7.4.orig/src/window.c	2008-08-15 15:32:16.000000000 -0400
+++ compiz-0.7.4/src/window.c	2008-08-15 15:36:19.000000000 -0400
@@ -1887,6 +1887,43 @@
     wa->screen		      = NULL;
 }
 
+Bool
+focusWindowAllowUnmanaged (CompWindow *w)
+{
+    if (w->attrib.override_redirect)
+	return FALSE;
+
+    if (!onCurrentDesktop (w))
+	return FALSE;
+
+    if (!w->shaded && (w->state & CompWindowStateHiddenMask))
+	return FALSE;
+
+    if (w->attrib.x + w->width  <= 0	||
+	w->attrib.y + w->height <= 0	||
+	w->attrib.x >= w->screen->width ||
+	w->attrib.y >= w->screen->height)
+	return FALSE;
+
+    return TRUE;
+}
+
+Bool
+isWindowDesktopHideable(CompWindow *w)
+{
+  CompDisplay   *d = w->screen->display;
+  CompOption    *st = &d->opt[COMP_DISPLAY_OPTION_HIDE_SKIP_TASKBAR_WINDOWS];
+  
+  if ((w->wmType & ~(CompWindowTypeDesktopMask | CompWindowTypeDockMask)) &&
+	    (!(w->state & CompWindowStateSkipTaskbarMask) || st->value.b) &&
+	    !w->inShowDesktopMode &&
+	    !w->grabbed &&
+	    focusWindowAllowUnmanaged (w))
+	  return TRUE;
+	else
+	  return FALSE;    
+}
+
 void
 addWindow (CompScreen *screen,
 	   Window     id,
@@ -2271,6 +2308,17 @@
 		      w->attrib.x, w->attrib.y,
 		      w->attrib.width, ++w->attrib.height - 1,
 		      w->attrib.border_width);
+
+
+  if (isWindowDesktopHideable (w))
+  {
+	    unsigned long data = 0;
+	    /* Declare that we are no longer showing the desktop */
+	    XChangeProperty (screen->display->display, screen->root,
+		       screen->display->showingDesktopAtom,
+		       XA_CARDINAL, 32, PropModeReplace,
+		       (unsigned char *) &data, 1);
+  }
 }
 
 void
@@ -4528,6 +4576,7 @@
 showWindow (CompWindow *w)
 {
     Bool onDesktop = onCurrentDesktop (w);
+    unsigned long data = 0;
 
     if (!w->managed)
 	return;
@@ -4569,6 +4618,15 @@
     XMapWindow (w->screen->display->display, w->id);
 
     changeWindowState (w, w->state & ~CompWindowStateHiddenMask);
+
+  if (isWindowDesktopHideable (w))
+  {
+    /* Declare that we are no longer showing the desktop */
+    XChangeProperty (w->screen->display->display, w->screen->root,
+       w->screen->display->showingDesktopAtom,
+       XA_CARDINAL, 32, PropModeReplace,
+       (unsigned char *) &data, 1);
+  }
 }
 
 static void