>>>>What is the default value for the column? Check this blog post
>>>>
>>>>http://blogs.lessthandot.com/index.php/datamgmt/dbprogramming/best-practice-don-t-not-cluster-on-uniqu/
>>>
>>>

ALTER TABLE [dbo].[Transactions] ADD  CONSTRAINT [DF_Transactions_GUID]  DEFAULT (newid()) FOR [GUID]

>>>
>>>thanks, I'll read the blog.
>>
>>With NEWID() as default you definitely do not want to have it clustered.
>
>I should be able to change the default to newsequentialid(), but I think what happened here is that I was generating lots of records relying on the default, but the code actually uses .NET to generate the Guid and not rely on the default. I wonder if there is a newsequentialid for c#.... :)

There is no newsequentialid in C# but I think I read about some implementations. Check this blog post

http://blogs.msdn.com/b/dbrowne/archive/2012/07/03/how-to-generate-sequential-guids-for-sql-server-in-net.aspx

David Browne is a great developer from MS and he is very helpful in MSDN forums. I also asked a few questions of him privately.