I have a database and tables in my SQL Server 2008 that came over from 2005 version when I upgraded. I needed to make some changes to a couple of tables and I am restricted from doing so. I added a column to a table in design mode (SSMS) and when I closed the designer I get the save question of which I answer yes. Then I get this message:

"Saving Changes is not permitted. The Changes you have made requires the following tables to be dropped & re-created. You have either made changes to a table that can't be re-created or enabled the option Prevent saving changes that require the table to be re-created"

What can I change to allow me to make changes to my tables? The owner of this database is sa and I am logged in as sa.
Thanks
Tim