Bug 299438 [CommonNavigator] CNF viewer state non properly reset when NCEs are activated or deactivated
The map of the objects to the NCEs should be reset whenever the NCEs associated with the viewer to change to avoid having stale label information. This has shown up when looking at the CNF tests that change the viewer.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/StructuredViewer.java
*            a double-click listener
	 */
	public void removeDoubleClickListener(IDoubleClickListener listener) {
		doubleClickListeners.remove(listener);
	}
	/**
	 * Removes the given filter from this viewer, and triggers refiltering and
	 * resorting of the elements if required. Has no effect if the identical
	 * filter is not registered. If you want to remove more than one filter
	 * consider using {@link StructuredViewer#setFilters(ViewerFilter[])}.
	 * 
	 * @param filter
	 *            a viewer filter
	 * @see StructuredViewer#setFilters(ViewerFilter[])
	 */
	public void removeFilter(ViewerFilter filter) {
		Assert.isNotNull(filter);
		if (filters != null) {
			
			
			for (Iterator i = filters.iterator(); i.hasNext();) {
				Object o = i.next();
				if (o == filter) {
					i.remove();
					refresh();
					if (filters.size() == 0) {
						filters = null;
					}
					return;
				}