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.

• Foreign diacritical marks do not display in a TextBox control or a RichTextBox control in an Out-of-Browser (OOB) application on a Macintosh computer.

Note: A diacritic is a special mark added to a letter to indicate a different pronunciation, stress, tone, or meaning. Acute and grave accents, tildes, and cedillas are examples of diacritics.

• Before you apply this update, a Silverlight 4 OOB application can enable an update only when the application is signed with matching certificates that have not expired. This update relaxes this restriction. After you apply the update, an OOB application can enable an update if the following conditions are true:
• Both the new application and the old application have valid signatures.
• The new application is signed with a trusted certificate.
• The Subject and the Issuer of the certificate that is used to sign the new application match those of the certificate that is used to sign the old application.