Thanks for the question. I missed a point, but learned something new.

The reason I missed a point is because, when doing some research, I found this text:

"If you attach a database with the same service broker identifier as an existing database, SQL Server deactivates Service Broker message delivery in the database being attached."

(This is from http://msdn.microsoft.com/en-us/library/ms166057%28SQL.90%29.aspx).

The quote specifically mentions attaching, but since the entire page is about attach and restore, I assumed that the restore behaviour would be identical. Obviously not.