Yes, sorry about this. The tutorials on the pre-release have not bee updated so you are getting the error because the PrimaryKeyField is now an array instead of a String. THis was added to support compound primary keys. You can resolve this error yourself if you would like by changing the line in error to something like this:
Me.PrimaryKeyField = New String() {"TheFieldname"}
ALso, we will have the official 1.4 release available next week and the tutorials will be updated as well Let me know if this doesn't answer your question.