Bug 274236 [CommonNavigator] Incorrect check for existence of item in contribution memory
The check in the NavigatorContentService.rememberContribution() should be containsKey(), not containsValue()
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/NavigatorContentService.java
* @see
	 * org.eclipse.ui.internal.navigator.INavigatorContentService#restoreState
	 * (org.eclipse.ui.IMemento)
	 */
	public void restoreState(final IMemento aMemento) {
		synchronized (this) {
			List runnables = new ArrayList();
			for (Iterator extensionItr = getExtensions().iterator(); extensionItr
					.hasNext();) {
				final NavigatorContentExtension element = (NavigatorContentExtension) extensionItr
						.next();
				ISafeRunnable runnable = new ISafeRunnable() {
					public void run() throws Exception {
						element.restoreState(aMemento);
					}
					public void handleException(Throwable exception) {
						NavigatorPlugin.logError(0,
								"Could not restore state for Common Navigator content extension" 
										+ element.getId(), exception);
					}
				};
				runnables.add(runnable);
			}
			for (Iterator iterator = runnables.iterator(); iterator.hasNext();) {
				ISafeRunnable runnable = (ISafeRunnable) iterator.next();
				SafeRunner.run(runnable);
			}
		}
	}
	/*