All updates to Microsoft Silverlight include functional, performance, reliability and security improvements and are backward compatible with web applications built using previous versions of Silverlight.

• Fixes an issue where Office 365 customers may see a security risk prompt when using SharePoint
• Fixes an issue where nested popup controls cause a memory leak
• Fixes an issue in IE9 where Switching a Silverlight video from full screen back to normal dimension results in rendering issues with the page
• Fixes an issue in the Silverlight DataGrid where rows are garbled when columns outside of the viewing area are of different sizes
• Fixes an issue in the Silverlight DataGrid where memory is leaked when using INotifyDataErrorInfo.ErrrorsChanged event
• Adds adds support for setting the InnerException on IsolatedStorage exceptions if a registry key is set. The registry key is HKLM\software\Microsoft\Silverlight\IsolatedStorageInnerExceptionsAllowedDomains and its value is a comma separated list of domains
• Fixes an issue where Controls are leaked with INotifyDataErrorInfo.ErrorsChanged event subscriptions