1. You can get 404 if you have changed the news item url or the page where NewsView control resides.
2. As you might have noticed from the other post the index is partially updated. If you want to update the entire index you have to do it manually or programmatically as shown in the referenced link.
the Telerik team
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Telerik Public Issue Tracking
system and vote to affect the priority of the items