title: GUID of 00000000-0000-0000-0000-000000000000 causing merge index violation
body: <p>Our developer has a linq-2-sql project that talks to my database.  The database is involved in merge replication.  It has been in use for some time and was working fine.  A recent table was added to the schema and now is causing problems when new records are added.</p>
  
  <p>The user get's an error message stating that the index related to the guid that merge replication automatically creates is violating a unique constraint.</p>
  
  <p>From what I can tell the table isn't any different than others that are involved.  I have recreated the entire replication publication/subscription model from scratch and everything continues to work but that one table.</p>
  
  <p>Anyone have any ideas?  The guid being created appears as 00000000-0000-0000-0000-000000000000 which would explain why it's a duplicate.  Why is a valid guid not being created by linq?</p>