public void postWindowOpen() {
	final PreferenceManager preferenceManager = PlatformUI.getWorkbench().getPreferenceManager();
	final IPreferenceNode[] rootSubNodes = preferenceManager.getRootSubNodes();

	// @see Bug #191 in general/bugzilla/index.html
	final List<String> filters = new ArrayList<String>();
	filters.add("org.eclipse.compare");
	// The following three preferences are shown because the Toolbox uses
	// the local history feature provided by o.e.team.ui
	filters.add("org.eclipse.team.ui");
	filters.add("org.eclipse.ui.trace");
	filters.add("org.eclipse.jsch.ui");

	// Filter out Pdf4Eclipse preference page.
	filters.add("de.vonloesch.pdf4Eclipse");
	
	// Filter out GraphViz
	filters.add("com.abstratt.graphviz.ui");
	
	// Clean the preferences
	final List<IPreferenceNode> elements = preferenceManager.getElements(PreferenceManager.POST_ORDER);
	for (Iterator<IPreferenceNode> iterator = elements.iterator(); iterator.hasNext();) {
		final IPreferenceNode elem = iterator.next();
		if (elem instanceof IPluginContribution) {
			final IPluginContribution aPluginContribution = (IPluginContribution) elem;
			if (filters.contains(aPluginContribution.getPluginId())) {
				final IPreferenceNode node = (IPreferenceNode) elem;

				// remove from root node
				preferenceManager.remove(node);

				// remove from all subnodes
				for (int i = 0; i < rootSubNodes.length; i++) {
					final IPreferenceNode subNode = rootSubNodes[i];
					subNode.remove(node);
				}
			}
		}
	}
	super.postWindowOpen();
	
	// At this point in time we can be certain that the UI is fully
	// instantiated (views, editors, menus...). Thus, register
	// listeners that connect the UI to the workspace resources.
	ToolboxLifecycleParticipantManger.postWorkbenchWindowOpen();
}