Behavior of query differs for byte data

MORE INFORMATION

Steps to Reproduce Behavior

1. Start Microsoft Access.
2. Create a new table and save it as Table1. Add the following field to the table:

      Table: Table1
      ------------------
      Field name: Field1
      
      Data Type: Number
      Field size: Byte

3. Enter the following data in the first three rows:

   10, 15, 20

4. Close the table.
5. Create an update query based on Table1. To do so, follow these steps:
   1. In the Database window, click the Query tab, and then click OK.
   2. In the New Query box, click Design view, and then click OK.
   3. In the Show Table box, select Table1, click Add, and then click Close.
   4. Add Field1 to the query grid.
   5. On the Query menu, click Update Query.
   6. In the Update To row, type [Field1] * 2.
6. Run the query four times. Click Yes to each confirmation message.
   
   Note that when the value that should be returned is greater than the Byte data type size limitation of 255, an incorrect value is returned to the field. In the above example, the values that are returned each time that you run the query are as follows:

   Query	Returned Values
   One	20, 30, 40
   Two	40, 60, 80
   Three	80, 120, 160
   Four	160, 240, 64