I am receiving the following error

     Cannot insert the value NULL into column 'Address1', table 'My3DRooms.dbo.Location'; column does not allow nulls. INSERT fails.

SQL Profiler shows the following:

exec sp_executesql N'SET NOCOUNT OFF INSERT INTO [Location]([LocationId], [Address1], 
[City], [Region], [PostalCode], [Country]) 
VALUES (@LocationId, @Address1, @City, @Region, @PostalCode, @Country)',
 N'@LocationId uniqueidentifier,@Address1 varchar(8000),@City varchar(8000),
@Region varchar(8000),@PostalCode varchar(8000),@Country varchar(8000)', 
@LocationId = 'AB7FF6CD-2F26-4F1E-AB23-9AB3015ADDB8', 
@Address1 = NULL, 
@City = NULL, 
@Region = NULL, 
@PostalCode = NULL, 
@Country = NULL

But the weird part is that when I check the properties of my Location variable in the VS IDE, it shows that Address1 is NOT null, but in fact the "123 Main St." that I entered as a test value. Any idea what might be wrong?

David, you are THE MAN!  It's been months since I've been down and dirty with ES in my last project and apparently in the meantime I had forgotten such simple things as calling EndEdit on my bound entity.  Once I added that, saving worked!

Thanks!  You saved my weekend!