Bug 305375 [ui] Many dialogs about unavailable sites
I20100309-0100 I ran a "Check for Updates" immediately after my machine had come out of standby. I don't think the wireless had fully connected yet, and the check for updates failed (fine). However, I got a half dozen nested dialogs about each of the sites that it could not find. They were all stacked on top of one another, and I had to dismiss each one individually. I would expect it to accumulate this into a single dialog rather than one dialog per repository.
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/NavigatorContentService.java
* @see org.eclipse.ui.internal.navigator.INavigatorContentService#dispose()
	 */
	public void dispose() {
		if (navigatorSaveablesService != null) {
			assistant.removeListener(navigatorSaveablesService);
		}
		if (navigatorSorterService != null) {
			assistant.removeListener(navigatorSorterService);
		}
		synchronized (this) {
			for (Iterator contentItr = contentExtensions.values().iterator(); contentItr
					.hasNext();) {
				((NavigatorContentExtension) contentItr.next()).dispose();
			}
		}
		getActivationService().removeExtensionActivationListener(this);
		assistant.dispose();
		isDisposed = true;
	}
	protected void updateService(Viewer aViewer, Object anOldInput,
			Object aNewInput) {
		
		
		
		if (isDisposed)
			return;
		synchronized (this) {
			if (structuredViewerManager == null) {
				structuredViewerManager = new StructuredViewerManager((StructuredViewer) aViewer, this);
				structuredViewerManager.inputChanged(anOldInput, aNewInput);