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
*         <b>org.eclipse.ui.navigator.viewer/viewerContentBinding</b> to be
	 *         a root element or have a <b>triggerPoints</b> expression that is
	 *         <i>enabled</i> for the given element.
	 */
	public Set findRootContentExtensions(Object anElement,
			boolean toRespectViewerRoots) {
		SortedSet rootExtensions = new TreeSet(
				ExtensionSequenceNumberComparator.INSTANCE);
		if (toRespectViewerRoots
				) {
			NavigatorContentDescriptor[] descriptors = CONTENT_DESCRIPTOR_REGISTRY
					.getAllContentDescriptors();
			NavigatorContentExtension extension = null;
			for (int i = 0; i < descriptors.length; i++) {
				if (isActive(descriptors[i].getId())
						&& isRootExtension(descriptors[i].getId())) {
					extension = getExtension(descriptors[i]);
					if (!extension.hasLoadingFailed()) {
						rootExtensions.add(extension);
					}
				}
			}
		}
		if (rootExtensions.isEmpty()) {
			return findContentExtensionsByTriggerPoint(anElement);
		}
		return rootExtensions;
	}
	/**
	 * Search for extensions that declare the given element in their