Symptoms
When you upgrade an instance of SQL Server to SQL Server 2008, some client-related protocol settings are not automatically applied to the SQL Server 2008 client. For example if you have enabled Secure Socket Layer Encryption (SSL) on a SQL Server 2005 instance either by turning on the Force protocol encryption option in Client Network utility or by using the Properties page of SQL Native Client Configuration in SQL Server configuration manager, the setting is not preserved when you upgrade that instance to SQL Server 2008.
Resolution
This behavior is by design.