Indeed you are right. It seems that there is a problem with the RSS feeds that we need to investigate.
Meanwhile you could use this link to access the release notes:http://www.telerik.com/products/silverlight/whats-new/release_notes/q3-2011-sp1-version-2011-3-1220.aspx.
All the best,
the Telerik team
Explore the entire Telerik portfolio by downloading the Ultimate Collection trial package. Get it now >>