You create a new table in Datasheet view in Microsoft Office Access 2007 or in Microsoft Access 2007. Every time that you press ENTER to add a new field to the table, the ID field value is incremented by one. For example, if you add five fields to the first row of data before you save the table, the ID field value is incremented to 5.
To work around this problem, perform one of the following actions:
Add a second row of data before you add a new field to the table.
Save the table before you add a new field to the table.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Steps to reproduce the problem
On the Create tab, click Table.
In Datasheet view, type SampleData in the Add New Field box, and then press ENTER.
Type SampleData2 in the Add New Field text box, and then press ENTER.