Why can't I use NEWSEQUENTIALID() as the default value for my column?

I'm trying to create a table in Management Studio and after reading about the new (from SQL 2005 on) NEWSEQUENTIALID() function, thought I'd give it a go.

This is what I'm doing:

But it's not letting me. The error message I get is:

'FormTemplate (Forms)' table - Error validating the default for column 'FormTemplateId'.

Am I missing a trick here? I'm definitely running SQL Server 2008 R2.

Use CREATE TABLE, not the GUI.

This is a bug in SSMS, already reported here as well as here on Connect.

StackExchange Database Administrators Q#7249, answer score: 19