sp_configure 'filestream access level',2
and then this:
RECONFIGURE WITH OVERRIDE
in the database in question (not in the master db)
I also enable these two options as well (but don't know if they have to be enabled):
Source: http://blogs.msdn.com/b/chrissk/archive/2009/02/08/example-using-transactional-replication-with-filestreams-in-sql-2008.aspx