>Hi,
>
>A customer just called me and reported that one of the main tables of the application had the PK (visible but not editable by the user) increased by about 1000 records. This field, Order Number, was about 158 yesterday and now they see it as 1136 (around that). I remoted to the SQL Server and indeed see that the PK number skipped many records. This field is PK and it is Identity with increment 1.
>Any possible explanation for how this could occur?

This is a known problem with identity column that occurs when the server is re-started and this is by design according to MS

https://connect.microsoft.com/SQLServer/feedback/details/739013/alwayson-fail

https://social.msdn.microsoft.com/Forums/sqlserver/en-US/3d256650-0e94-4d0f-8b52-0ba6e1903215/primary-key-auto-incrementing-by-1000-instead-of-1?forum=transactsql