Sharepoint 2010 External Content Type Create / Update Operations (SQL Server Replication Issue)

I am unable to INSERT or UPDATE an item in my external list created from an external content type

Here is the error:

I have created an external content type called "Product Status". It has all the operations possible e.g. Read / Create / Upd开发者_如何学Goate etc

Here is the table structure:

The rowguid field as far as I know was created by the SQL Server replication.

When creating my external content type, it does not allow me to not select the rowguid!

Update Operation

It seems that when it creates the external content type "Product Status", the update operation is trying to update the rowguid to null which it cannot be. It shouldn't update that field at all, however I cannot exclude it from my external content type item created.

Replication was no longer required on the server, so it was removed. Working fine now.