This technote should solve your issue even if you have not moved the databases:
http://seer.entsupport.symantec.com/docs/318791.htm
SQL Service Broker warning when restoring a customer database to a different server
SQL Server may record the following warning message in the event log if you restore a Discovery Accelerator customer database to a different server than that on which it originally resided:
Service Broker needs to access the master key in the database
'database_name'. Error code:25. The master key
has to exist and the service master key encryption is required.
You can suppress this warning message by using the following SQL Server command to create a master key for the database:
CREATE MASTER KEY ENCRYPTION BY PASSWORD = 'password'
For more information, see the following article in SQL Server 2005 Books Online:
http://msdn.microsoft.com/en-us/library/aa337551(SQL.90).aspx
Synchronization errors after you rename the SQL Server computer