I\'ve genereated a schema for my (SQL 2005) db using SchemaExport, and it\'s created a table
CREATE TABLE [dbo].[hibernate_unique_key](
[next_hi] [int] NULL
NHibernate expects to find a value that stores the current hi value in that table, ie it first runs something like:
current_hi = [SELECT max(next_hi) FROM hibernate_unique_key].
So all you need to do is seed that table with an initial number, ie:
INSERT INTO hibernate_unique_key(next_hi) VALUES (0)